Sometimes working until 8:30PM gets to me. I don't have any issues with any of my students, but after a while I just want to finish up and get home. Not a big deal because tutoring is still pretty much a blast. I never really expected that I'd enjoy sitting around doing different kinds of math all day, but I do. Is it something I want to make permanent? Not really - but it's always really nice to know that I have this skill.