Start talking about something and get so lost on tangents trying to explain all the precursory information they need to understand that original thing I haven’t explained yet that I’m now debating something entirely unrelated and have forgotten the original point I’m trying to make.
Bonus points if I end up losing my train of thought during one of the tangents and now don’t even know what I said two seconds ago and have still forgotten the original point I was trying to make.
Also not being able to do simple things I plan/need to do, like laundry or writing an email, but then spend 4hrs straight building something incredibly complex from scratch just to test a random theory I had that has no other usefulness.