It comes down to trying to have a little balance in your life. It's been said that programming is an art form. Those who take pride in their work try to build something elegant that is not only functional, but also a beauty to look at and work on. If you are not careful it can also become an obsession that can dominate your life. Being an introvert just compounds it.

Unlike some other types of art, software is never really finished. I don't think that painters or sculptors regularly revisit their creations to try and improve them. They don't have versions 2, 3, or 4 of a painting or statue. The closest thing might be writers who sometimes have multiple editions to their books. There is always something to do to improve a piece of software so it can keep you up too late at night because it is just a compile or two away.

Oops, gotta go, I just thought of a new feature for my project...