"You don't learn programming by theory, you learn it by hacking"
I'm in a training course for MS SQL Server 2005, and the teacher said: "how did I learn programming? I went to a magazine and typed in some code and watched it run. You don't learn programming by theory, you learn it by hacking."
I bit my tongue because I'm sure many Haskellers (mathematician like Cale and physicists like David Roundy) did learn Haskell by placing theoretical expectations on how the language should work from a theoretical perspective and then seeing how haskell implemented their theoretical expectations.