An idea in your head is a rumor. An idea on paper is a fact you can fix.

In your head an idea keeps quietly editing itself to stay undefeated. Every time you check on it, it has already adjusted around the problem you were about to notice. Written down it stops moving, and for the first time it is specific enough to be wrong. That is not a downgrade, it is the only condition under which it can improve.

Give it five minutes and the worst possible draft. Bullet points in a notes app on the bus count completely.