This is how I got interested in music: -
http://www.youtube.com/watch?v=MPNxT66n_lw
Learnt to play oh when the saints, greensleeves, happy birthday etc on it. But I didn't come from a family that exactly encouraged my interest in music so it sort of died there. For years I thought the way to play music was with numbers! 1345, 1345, 1345, 3132 is the opening sequence to oh when the saints. I still remember.
Bought a full size electronic keyboard a few years ago and found playing it very therapeutic so eventually upgraded to the proper thing, a big jump I leant.
I'm not classically trained, but may do that when I have some more time, but I'm quite good at remembering long sequences of keystrokes, so can bang out a few tunes. I sort of learnt in reverse, learn the tune, see the sequence of chords and the melody and that helped me understand music a bit better.
It's about the only thing I can do that takes my mind of everything else and that's the main reason I enjoy doing it.