Nothing on pet ownership? Because after an hour of my cat climbing all over me from 3-4 am this morning I finally had to lock him out of my room. He's a nice boy, but I didn't appreciate his affection at that hour.
I've noticed my cats seem to get unsettled and "wild" as if in response to the disruption of my own natural wake/sleep rhythms. Both usually sleep in bed with me and generally like to be where I am, and I think it throws them off when I occasionally burn the midnight+ oil.
Both of mine like sleeping on the bed with me, though they don't like sleeping with each other. I think they've worked out a time share arrangement, because they'll rotate through the night. I rarely stay up significantly later than my norm, but I have a feeling your assessment is spot on. I'm going out of town this weekend, so I've been cleaning and sorting stuff for packing. Max knows what this means, and he doesn't like it. Like you said, it throws them off and makes them a little crazy.