I'm a bit late here, but my response seems different enough to the others posted here to warrant replying!

My brain is abysmally bad at storing trains of thought/deduction that lead to conclusions. It's very good at having exceptionally long trains of thoughts/deductions. It's quite good at storing the conclusions of my trains of thoughts, but only as cached thoughts and heuristics. It means that my brain is full of conclusions that I know I assign high probabilities to, but don't know why off the top of my head. My beliefs end up stored as a list of theorems in my head, with proofs left as an exercise to the reader. I occasionally double-check them, but it's a time-consuming process.

If I'm having a not very mentally agile day, I can't off the top of my head re-prove the results I think I know, and a different result seems tempting, I basically get confused for a while until I re-figure out how to prove the result I know I've proven before.

Basically on some days past-me seems like a sufficiently different person that I no longer completely trust her judgement.