Three lines a night is small enough to actually keep and specific enough to pattern-match later. Sixty days is long enough that the pattern stops being about the week you had and starts being about you. The order matters: friction first, format second, interpretation third, distance fourth, and only then a decision.
Step 1: Put the notebook where you sleep
Friction decides whether this habit survives week one, so kill every excuse before writing a single line. Put the notebook physically on the pillow or nightstand you touch last, clip the pen to the cover with a rubber band, and open it to a blank page before you leave the room in the morning. Why the bed and not a desk: a desk requires a decision to go there, a pillow does not. Example: if you charge your phone across the room, the notebook should sit closer than the phone. What kills this is relocating the habit into your phone's notes app because it is already in your hand — same words, less friction, but it becomes one more thing you scroll past and dismiss. Three lines is the floor, not a target; writing two still counts and keeps the run alive.
Step 2: Two facts, then one feeling
Two lines of plain fact first, then one line of feeling — the order matters more than you would guess. Starting with what happened defeats the blank page, because facts are cheap to recall; starting with feelings invites either a spiral or a blank stare, and by the time you reach line three you have done something useful: named the mood instead of just sitting in it. Keep it unedited. Write 'missed the bus, ate lunch at the desk, argued with Sam' and then 'flat and a bit resentful.' No transitions, no summary sentence, no self-analysis. What derails this is turning it into a diary entry — three paragraphs, one entry, then two nights skipped because it now feels like homework. If line three reads identical to yesterday's, that is data, not failure; note it and move on.
Step 3: One truth every Sunday
By Sunday you have six or seven nights of raw material, which is exactly enough to see something invisible on any single night. A truth is one sentence about yourself that would still be true next month: not 'I am exhausted' (a state), but 'I agree to things on the phone before checking whether I have the time.' Write it in the same notebook, dated, on the page after that week's last entry — not in a separate document, or you will have two systems and quietly abandon one. Read the week's three-line entries first, then write the truth while they are still in view. The common shortcut is writing a resolution ('I will stop doing that') or a compliment ('I handled that well'). Both are plans and praise, not observations. A real truth is uncomfortable precisely because it keeps showing up.
Step 4: Reread week one at week four
Distance is what makes this step work, which is why it sits at week four rather than week two. Week-one you is nearly a stranger by now, and rereading a stranger's sentences lets you see repetition you would have defended against live. Set aside twenty minutes, read week one start to finish without writing in the margins, then close the book and write one line on the current page: the pattern you noticed. Example: three separate week-one entries mention the same coworker's name, and only the third admits you were annoyed. Where people go wrong is rereading to grade themselves — fixing grammar, wincing at the whining, deciding whether they 'did it right.' That turns an observation tool into a performance review. Read for recurrence, not quality. If nothing surfaces, read the same week again in seven days.
Step 5: The letter with your top five truths
Sixty days of entries produce roughly eight or nine truths, and the letter forces the cut to five. That cut is the real work: choosing what still holds once the mood of the week has worn off. Open the notebook to your truth pages, list every one, then rank by which still sting or still explain something you did this month. Write the letter in second person, dated and addressed to a specific day — one year out is a reasonable default — and name incidents: 'In month three you will want to quit something. You have done that twice now, in 2019 and 2022.' Seal it, write the open-date on the envelope, and keep it where you store documents you actually revisit, not in a drawer of old notebooks. The failure mode is general advice to an abstract person instead of your own entries quoted back at yourself.
A reminder in a phone app disappears the moment it is dismissed, leaving no trace it ever existed; a paper strip taped to the mirror gets visibly shorter as steps are cut off and stays there until the last one is gone. Sixty days of strips is a stack you can hold, and every truth inside it was written before you knew how the story ended.