I usually have a hashtag for every subject I'm interested in, if I should happen to learn something new that day, plus a few others like #dream.

Sometimes I even think about building a new custom notes app, that's purely just a Facebook Messenger window with yourself, with search and a hashtag list, or switching to logseq.

I usually follow up on mistakes by looking for patterns and... generally just avoiding the conditions that led to the mistake entirely.

Like, one of my personal rules is "There is no later". I try not to rely on memory for anything important, I assume the concept of remembering something later is only accessible to computers and sticky notes.