I'm also like this. Some part of me feels that any moment spent not honing a skill / advancing in some way is a wasted one. I know it's a bs perspective, but still I find myself taking it constantly.
I do manage to force myself out of this way of thinking from time to time, but it requires conscious effort to do so.
I imagine this forum has its fair share of people who fall for this "overachiever fallacy". I'd be curious to hear how others deal with it.