Why do i think more deeply when i'm in a sad mood?

If you are living in the northeast, you are probably surrounded by clouds and a low atmospheric pressure most every day. Lack of sunlight tends to make people depressed and more lethargic than usual. In these "dark" days, people tend to become depressed and more withdrawn than usual. You focus on things more during these times more than you normally would. If it was sunny and nice outside, you would probably feel happier and more optimistic. You wouldn't be so apt to want to write songs that are melancholy. The weather influences us more than you think. You are not weird. And you are not alone. There are plenty of us out here who feel just like you do.