I used to be able to play a whole bunch of reasonably fast, requires-both-hands (not just chords either) self-taught piano songs (e.g. The Entertainer) when I was younger. I can’t recall how to play them at all anymore.
I thought I had muscle memory for it but apparently not. In fact, when I stopped playing for about 5 years I went up to a piano (keyboard) in a store with the intention of playing one of those songs… Nope! Couldn’t do it.
I bet if I took the time to re-learn those songs I’d do so much faster now but it would still take a lot more effort than a normal person I think. Then my problem would be remembering all the songs! I can only remember two but I know I could play several songs back in the day 🤷