Perell asks Popova about the relationship between diaries and memoir. She gives him a line that lands as a small bomb.
Memoir is just the Instagram version of the diary.1
She laughs after she says it. She then unpacks what she means. Up until the end of the 19th century, memoir as a term meant somebody else writing to commemorate somebody who died. For example, when Margaret Fuller died, Emerson wrote Memoirs of Margaret Fuller that other people contributed to. It was kind of other people remembering the person — as opposed to the person self-reporting their life. And then it changed.
The word memoir used to mean commemoration by others — a composite portrait built from many people's recollections of a now-dead figure. Sometime around 1900 the word shifted to mean self-reporting by the still-living person. The same word now names two operationally different things.
The self-reporting version is what Popova compares to Instagram. The memoir-writer is curating a self-presentation for an audience. The audience is the entire point. The self-reporting is shaped by audience-awareness throughout. The result is the person's account of themselves as they want to be seen.
The diary, by contrast, is the person's account of themselves when no one is watching — at least in the ideal case. The diary isn't curated for audience. The diary is unfiltered or close to it. The diary preserves the texture of who the person actually was, not the texture of who the person wanted to be seen as.
The distinction is operationally substantial. A biographer using a memoir has different material than a biographer using a diary. The memoir gives you the persona. The diary gives you the person. Both are real. They aren't the same.
The full set of distinctions across diary, letter, memoir, and biography.
Diary — written by the person, ideally for no audience. Records what the person actually thought, observed, felt. Most reliable as evidence of the person's interior. Least filtered.
Letter — written by the person, for one specific other person. Partly self-presentational (the writer is shaping themselves for the recipient) and partly genuine (the writer is talking to someone they trust). Less reliable than a diary, more reliable than a memoir.
Memoir (contemporary sense) — written by the person, for a public audience. Heavily self-presentational. Useful for understanding the persona the person wanted projected. Less useful for understanding the actual person.
Biography — written by another person about the subject, ideally based on substantial evidence. The mediating role of the biographer adds another layer of self-presentation (the biographer is also writing for an audience). Best when the biographer has access to the subject's diaries and letters.
Memoir (pre-1900 sense) — written by others to commemorate a now-dead figure, often composite. Similar to biography but typically more episodic and less narrative-arc-organized.
Each form gives the reader access to a different layer of the subject. A serious biographer reads all four — diary first, letter second, memoir last, with the older composite memoirs as additional perspective. Most readers don't read all four. Most readers read memoir, which is the most self-presentational and the least reliable.
Popova notices that the 200-year-old diary is more reliable than the contemporary memoir even though both are first-person. The reliability comes from the absence of audience-awareness. 19th-century diarists mostly didn't expect publication. The diaries from that era are closer to the unguarded interior of their writers than contemporary memoirs are.
There are exceptions. Anaïs Nin's 14-volume diary was written knowing it would be published. The diary is therefore partly memoir in form. The hybrid produces a particular kind of work — substantially less filtered than a contemporary memoir, substantially more filtered than a private diary. Worth knowing the hybrid exists so the reader can calibrate.
The contemporary memoir's structural problem is that the reader thinks they're getting the diary (the person's actual interior) when they're getting the memoir (the curated self-presentation). The form's marketing reinforces the confusion. The book is sold as the writer's truth. The book is in many cases the writer's persona-construction. Some memoirs are exceptionally honest. Most are partially constructed. The reader who doesn't know the distinction reads the construction as the truth.
This page pairs with Observation-to-Contemplation Diary Form (Popova) — that page describes what diary form does at its best; this page distinguishes it from adjacent forms. The two pages combined cover Popova's full account of life-writing forms.
It connects to Two Umbrellas: Truth vs Legacy Memoir Typology (Tucker). Tucker's typology distinguishes truth-memoirs (closer to diary-mode) from legacy-memoirs (closer to persona-construction). The two pages combined name the operational forms that result from the philosophical distinction Popova draws.
It sits in tension with Reader as Mirror, Not Information (Tucker) — Tucker's memoir-as-mirror frame depends on the memoirist running closer to diary-mode than to persona-construction-mode. The vault should hold the relationship: Popova's distinction is the categorical apparatus; Tucker's is the operational claim within the truth-side category.
Imagine four kinds of writing about Mary Shelley sitting on a desk.
The diary. Shelley's own. Written across decades, mostly without expectation of publication. Records what she ate, who visited, what she read, what specifically she observed in a particular morning's weather. Records the deaths as they happened, in the language she had at the moment. Unfiltered or close to it.
The letters. Shelley's correspondence with Percy when he was alive, with friends and family after his death. More performed than the diary — she was shaping herself for specific recipients. Still substantial truth-content, but filtered by relationship.
The memoir. Imagine Shelley had lived to write her own retrospective. The retrospective would have been substantially shaped by what she wanted readers to think. The Mary Shelley of the imagined memoir would be partly the Mary Shelley she wanted projected — wiser than the real one, more graceful in grief, more certain about her own life.
The biography. Several have been written. The good ones used the diary, letters, and the few records of how she presented in public. The biography integrates the layers. The reader of the biography is getting a composite that's been mediated by the biographer's editorial decisions.
A serious reader of Mary Shelley uses all four. The diary tells you who she was when no one was watching. The letters tell you who she was with specific others. The memoir-equivalents tell you how she wanted to be seen. The biography integrates the layers and tells you what to make of the differences. Most contemporary readers read the biography only, sometimes a few letters, almost never the diary. They get the mediated Mary Shelley, not Mary Shelley.
You read about historical figures. You want to know them better than the current reading-strategies are giving you. Three operational moves.
Start with the diary if it exists. Whitman's notebooks. Shelley's journals. Sontag's notebooks. Plath's journals. Woolf's diaries. The form is different from the books these writers published. The form is closer to who they were.
Add the letters next. Most major writers have published letter-collections. The letters give you the interpersonal version of the writer — how they were with specific people in specific moments. The shifts in voice across recipients are informative.
Use the memoirs (theirs) and biographies (others') as composites at the end. The composites are useful but they're not where the writer lives. The writer lives in the diary and the letters. The composites are how the world has organized them after the fact.
The reading order matters. Most readers do it backwards — biography first, memoir if available, letters if curious, diary almost never. The backwards order gives you the most-mediated material first, which shapes what you'll see in the less-mediated material when you finally get there. The corrected order — diary first — lets the writer arrive un-curated, before the world's framing has organized them.
You've collapsed when you treat what you've read in someone's memoir as who that person actually was. The memoir gives you who the person wanted to be seen as. The two might overlap substantially. They're rarely identical. Treating them as identical produces a reader who knows the persona and doesn't know the person.
You're reading well when you can distinguish the layers. This is the persona Sontag was constructing in her memoirs. This is the actual interior in her notebooks. Here's where the two converge. Here's where they diverge. The distinction-making is the discipline. The discipline gives you a richer picture than persona-only reading.
The biographical-method literature has substantial work on form-distinctions. Janet Malcolm's The Silent Woman (on Plath biography) is foundational. Carl Rollyson's work on the methodology of literary biography. The convergence across biographer-traditions confirms Popova's distinctions are operationally real.
The tension: the contemporary memoir genre has become substantial economically and culturally. Calling it the Instagram version of the diary could read as dismissive of an important form. Some contemporary memoirs are exceptionally honest and reach diary-level reliability. Tucker Max's frame (truth-memoir vs legacy-memoir) suggests the form can be run either way. Popova's distinction is structural; individual memoirists can resist the structural pull.
A second tension. Letters are increasingly being lost as a form. Most contemporary correspondence is email or text, often deleted or never archived. The biographers of 2100 will have substantially less letter-material for figures active now than the biographers of 2025 have for figures from 1850. The form is structurally endangered. The aggregate effect on future biographies is uncertain.
Spend a week reading the contemporary memoirs of public figures. You learn what the figures want to be known for. The book is what the figure decided to put in the world. The book is partly true and partly construction. You can tell the difference sometimes; sometimes you can't.
Spend the same week reading the published diaries of 19th-century figures. You learn what those people actually noticed on specific days. The notebook entries weren't decided for the world. They were written for the writer. The reader is overhearing rather than being addressed.
The two reading experiences produce different things. The memoir-week leaves you informed about the figures' positions and decisions. The diary-week leaves you having spent time with specific minds in their daily texture. Both are useful. The diary-week is rarer because most readers don't know diaries exist as a form to seek out.
Tucker Max and Popova converge on the importance of the diary as a form. Tucker calls it the vomit draft. Popova calls it the observation-to-contemplation diary. Different vocabularies, same operational form — writing that isn't curated for an audience. Both writers consider the form load-bearing for honest later work. The convergence is informative.
The form-distinctions show up in two adjacent territories.
Behavioral Mechanics: Persona Construction vs. Authentic Self — Influence and self-presentation literatures distinguish carefully between managed self-presentation (Goffman's frontstage) and backstage behavior (Goffman's backstage). The memoir-vs-diary distinction is the literary instance of the same distinction. The skilled reader of people knows to look behind the persona to find the person. The skilled reader of texts knows to look behind the memoir to find the diary. Same operation across persons and texts.
Eastern Spirituality: Anatta and the Question of the Real Self — Buddhist tradition complicates the diary-vs-memoir distinction interestingly. The tradition holds that there is no single real self underneath the social presentation. The diary's writer is one self; the memoir's writer is another. Neither is the real writer because no real-writer exists separable from the contexts in which the writer is operating. Popova's distinction holds at the conventional level; the contemplative tradition runs deeper than the convention. Both can be true. The diary is more honest than the memoir in the specific sense Popova means; both are still constructions in the sense the Buddhist tradition means. The vault should hold both layers.
The Sharpest Implication The contemporary publishing economy structurally rewards memoir over diary. Memoirs sell. Diaries are mostly published posthumously and are commercially marginal. Writers therefore have substantial incentive to produce memoirs and almost no incentive to maintain diaries. The aggregate effect is that the unfiltered interior of contemporary writers is being lost in real time. Future biographers won't have for contemporary writers what current biographers have for 19th-century writers. The loss is invisible to most contemporary writers (who don't realize their diaries would have mattered) and to most contemporary readers (who don't realize the form difference). The fix is upstream — would require cultural revaluation of unpublished writing. Unlikely in the short term.
Generative Questions