I used to hear faculty discussing department chairs as if they were another species, and I didn't understand how that could be: they came with the same training and did the same kind of research as normal faculty, so how could they be so different? But now that I have met so many of them, I understand.
They're academics, and yet they're politically conscious. They're cocky and excited, even if they're under-resourced and have a mediocre record. They're oh so nice, yet every discussion is a negotiation requiring some attention to strategic concerns. They promise a little as if it's a lot, and they promise something when they might not have anything.
The first times I saw these traits, I didn't realize it was part of a pattern, but now it's so clear.