Bus Ride Musings

Why is it that when I take the bus in the morning, every seat is packed thigh to thigh with people, but when I catch the bus home at night, people never seem to squeeze in as tight? There's always several "half seats" available on the long benches that no one seems willing to squeeze into.

What is it that makes people less likely to wedge themselves into a seat in the afternoon? Is it because we've all had a whole day to get stinky?