From today's Wall Street Journal

"Of all the gulfs in understanding at the office, among the most difficult to bridge is that between morning and night people. The conflict between the morning larks and the night owls would be the office equivalent of the Bloods versus the Crips if, at any given time, one gang weren't so pooped."

I've always been a morning person and the wife's a night owl. So I get it at home too.