For two months I noted every time I had that specific feeling — the one where you suspect you're about to be found out. Date, what triggered it, and one line about what happened next.

Forty-one entries. Reading them back as a dataset rather than as feelings was more useful than any amount of reassurance.

What triggered them

Almost nothing was about ability.

• Eleven were vocabulary. Someone used a term I didn't know. In nine of those, I knew the concept perfectly well under a different name.
• Nine were speed. Someone solved something faster than I would have. In roughly half, they'd solved that exact problem before.
• Seven were scope. Being in a conversation about a system I'd never touched.
• Six were silence. Not understanding something and not asking.
• The remaining eight were, as far as I can tell, genuinely about not knowing something I should have.

So: eight out of forty-one were the real thing. The other thirty-three were mostly translation problems and comparison artifacts.

The one that changed my behaviour

The "silence" category. Six times I didn't understand something and didn't ask, and in every single case the confusion persisted and cost me time later.

Not asking is the only one of these where the feeling causes the deficit. The others are misreadings. That one is self-fulfilling.

I've gotten better at asking. It's still the hardest line in a meeting to say and it still costs me something every time.

The eight real ones

These were useful. Genuinely not knowing something you should know is just information. Each of the eight became a thing I went and learned, and I can point at all eight.

That's the reframe I got from the exercise: the feeling isn't a liar. It's a badly calibrated detector. It fires on vocabulary and speed, which are noise, and it also fires on real gaps, which are signal. The job isn't to silence it. It's to ask which of the five categories this one is.

What I'd tell someone starting out

Write them down. Not to feel better — to get a denominator. "I feel like this constantly" and "this happened eleven times and nine were vocabulary" are very different problems, and only one of them has an action attached.