"I don't really know myself" gets said like a confession, as if self-knowledge were a possession some people have acquired and others simply haven't. That framing makes the whole thing sound like a one-time achievement — get there, and you're done. It's a strange way to talk about something that, for almost everyone who claims to have it, is really an ongoing habit of checking your assumptions against what you actually do, not a fixed state you arrive at once.
The gap between believing and checking
Most people have a working theory of their own personality — "I'm pretty patient," "I don't really get jealous," "I'm a good listener" — formed early and rarely re-examined. The theory isn't necessarily wrong. It's just untested, in the specific sense that nothing forces it to meet actual evidence unless something goes wrong loudly enough to make the gap impossible to ignore. Self-knowledge, in the sense that's actually useful, isn't the theory. It's the habit of checking the theory against what actually happens, and updating when the two don't match.
That's uncomfortable in a specific way abstract self-reflection usually isn't. "Am I a patient person" invites a flattering answer with no real cost to getting it wrong. "Was I patient in that specific conversation on Tuesday, the one where I cut my partner off twice" is harder to answer generously, and it's the version that actually produces information.
Why most people never build the habit
Checking requires something to check against — a specific memory, a pattern someone else pointed out, a score from something structured enough to disagree with your own account of yourself. Without that, the theory just runs on repeat, reinforced by nothing but its own familiarity. It feels like self-knowledge because it's been believed for a long time, not because it's been tested recently.
What actually changes it
The people who report a real, felt sense of understanding themselves usually aren't the ones who had one clarifying insight. They're the ones who've built some regular way of getting disconfirming evidence — direct feedback they didn't ask to hear, a structured measurement that occasionally tells them something their own account wouldn't have, a habit of actually noticing when their behavior contradicted what they expected of themselves. The insight, when it comes, is usually just the moment the gap between the theory and the evidence finally got too big to keep ignoring.