When I'm tired, everything annoys me. An insect crawling across my desk becomes rage inspiring (and I squash it).
When I'm well slept, I'm generally a really calm person, with the exception of about 400 things, which I can't list due to lack of memory of what they are, and the excessive size of the list. So, I'll shorten it to three things:
When people push their own (flawed in my opinion) views on me.
When I'm denied something (tangible or intangible) that other people get, due to crappy circumstances.
People acting like assholes to nice people "just 'cos".