Don't get me wrong here, I love helping people and I even think that teaching others how to do something is a good way to keep yourself sharp. But, when you don't have time to teach them, you kind of miss out on that and you'll be "helping them" again next week. I think I make it pretty obvious when I absolutely can't be bothered at work, but it still happens. Someday I'd love to say what Dilbert said. "okay, while I'm working on your stuff, go grab me some lunch. thanks!"