Ah, you’re screwed. You’ve got a fatal combination of two factors working against you: you’re competent, and you care. Because you always get things done, people will continue to ask you to do things…because they know that you’ll get them done. You’re a victim of your own past success. Combine this with the fact that you actually care about students, the department(s) in which you teach, your colleagues, the discipline (continue this in ever-expanding outward concentric circles), and you’ve got the perfect recipe for Mondays from hell. Academe is one of those rare occupations in which you often don’t have something that you have to be doing, but you always have something you could/should be doing.