Re: Things you used to be able to do, but are unsure if you still can.
I was fluent in ASL (American Sign Language)...at least as fluent as a 5 year old is in any language...as a child. After my hearing was restored, though, I stopped using it, and was young enough to learn English just fine. Aside from a few words and phrases I can't speak ASL anymore.
I also forgot most of the French, Cantonese, and Japanese I learned, but I remembered most of the curse words!
I was a fairly good cellist as a kid (though no prodigy). I was principle cellist of the Seattle Youth Symphony when I was 15. Now I can hardly get through the easiest of the Bach Cello Suites! I think I was young enough when I learned, though, that if I practiced diligently I could pick it up again.