I learned how to read music when I was a kid; then I went through a couple of decades without playing a piano. Recently, I decided to try to learn to play boogie, so I bought the Tipitina arrangement, which was way beyond my skill level, and began plunking away. A few months of driving my family crazy later, and I can play it at 105bpm!
Cool. Didn't think I'd be able to do that.
But take away the sheet music, and I sit at the piano with a blank look on my face. Playing with other musicians? No clue. Tipitina taught me to use my hands better. How do I learn to make music without being spoon-fed?
I am learning to improvise using the blues scales and what's great is you can make up stuff and it sounds cool - no sheet music at all.