You know what today is, right?
That whole Daylight Saving thing is over, which means it gets darker earlier.
For a lot of people that might be a downer. You get home from work and it's pitch black outside. Maybe you skip that run because it just feels too cold and dark. Then you feel bad because you skipped your run, and you open a bottle of whiskey instead.
Ok, we're getting carried away, but you get the point. Some people are SAD in the winter months — literally SAD — they have seasonal affective disorder. They'd much rather frolic in the summer sun.