I'm an adjunct professor teaching philosophy. I've noticed that when I'm down, I tend to think more slowly and let awkward silences kick in more often. I also start to panic a bit when I get off track.

When I'm moderately up, it's good. I get a good dialogue going, and the energy seems to be kinda infectious. When I'm too up, I run through things too quickly, or focus more on what I'm interested in rather than covering what's actually on the syllabus, and get frustrated that no one is keeping pace.