My hairy paws torturing Beethoven earlier today:
When I bought this keyboard I attached little diagrams to its edge and drew notes on them. When I'm learning a piece I look up at the score, then find each note through those diagrams. This is an ass-backwards way of doing it. I'm sure it would have been better to directly memorize which key corresponds to which note. But I got used to the diagrams, and it kind of works.
I certainly wouldn't say that I can play the piano. I can play four classical pieces the way that a trained parrot can say a few human phrases. To me really knowing how to play is being able to play back any melody one has heard the way that almost anyone can sing or whistle any melody that he's just heard. I wouldn't even know how to begin doing that.
But as I've said, it's fun even at this level. I can play with the tempo of the pieces that I know, emphasize different things in them and really get into their moods air-guitar style, but for real. The sound does change to my command.
Through the thick wall of my musical ignorance I got a few dim glimpses of an intuitive understanding of how these pieces were made. Nothing I'd be able to verbalize, but there are certainly patterns to these things. That's interesting in itself.