I'm also getting my undergraduate degree in Theory & Composition, hoping to write music & implement sound for games. However, I'm also a programmer. It seems as though my hobby projects will alternate between music and programming; spend too much time doing either and I end up craving the other. This past summer, my dad got me a job writing software at his company, and they put me on a little R&D project. I learned so much every day about OOP (we implemented our part of the system in Java) and networking for those 2 months that I never got bored with it. Now, having totally binged on programming over the summer, I've found I've been prolific in my composition this semester. So for me, as long as I'm learning new something on whatever hobby project I'm working on, that apparently can keep me going for a while.
Just wanted to share, this is an interesting thread.