I voted other. I would have picked sometimes, but I don't think my reasons are stupid.

I haven't cancelled much, but when I have, I usually say why--sick or that the road is blocked. I think once I cancelled because I was too depressed to go, so I just said I couldn't make it, and left it at that.

I guess I tend to state the reason because I would like the same from my therapist if she has to cancel or reschedule.