Oh yeah, I totally get that, I'll be working on a piece and think it's perfect, then the next morning I notice so many things my ear had gotten used to and missed. And for the whistling, I really admire the fact you actually recorded it, that's super cool, and you definitely did it way better than I ever could've. You've kinda inspired me to try something like that in the future, and maybe incorporate my own piano playing into a piece.