All through high school and most of college I knew I wanted to be a programmer when I grew up. But when I was about to graduate I suddenly had to decide what kind of thing I wanted to program. I have many interests; too many to study them all. So I know a little about a lot of things but I have been unable to get jobs in those areas. (Graphics, compilers, AND operating system internals to name a few that the OP mentioned.) So basically since I couldn't decide I'm stuck with the "general" stuff. My experience is similar to OPs, basically, but I haven't figured out the solution. I have a vague plan of becoming either important enough at work to pick my projects and help with product strategy or else to become an independent developer.

Complicating this plan, though, is the fact that I put more emphasis on family than on work satisfaction. If I have to put up with a boring job but get to live in a nice house in a nice community and spend time with family, that might be worth it. I'm just not totally satisfied that it is yet. But I can't go risk everything in a San Fransisco start-up attempt.