What a good question. In order, I guess I mainly remember the sound of the music, and I just play back (or play along with) what I hear. I think my teacher does this, too. Ten times better, of course. Then, for reinforcement, I remember how certain things look on the landscape of the keyboard: the shapes of chords and sections of passages and how they fit in the hills and valleys. Then, at the beginning of treacherous passages that really need to start on a certain finger to avoid calamity, I whisper "two" or whatever, but not very often. I'm a bit cavalier about fingerings, and I only think about it when there's real danger ahead. I think this has caused my teacher to lose a little sleep, but actually, I believe he's the same way. He can play anything, and I believe could do it completely differently every time if he wanted to--but he doesn't tell his students he does this, or encourage them to do it. I've just noticed it. The visual score memory, I can call that up if I want to, but for me it's an extra step. It's not like I would remember what it looks like but not what it sounds like. I mean, if I know how it looks on paper, then I automatically know what it sounds like, so I'm still remembering the sound first, if that makes sense. It's pretty interesting that people do all this in such different ways.