I like to write sad songs. They're much easier to write and you get a lot more emotion into them. But people don't want to hear them as much. And radio definitely doesn't; they want that positive, uptempo thing.
You just write about things that happen.
A lot of times when songwriters get together and write a song... somebody will come in with a hook and a lot of times they come out with something that sounds a little crafty.
I don't write all my stuff. Everybody always thinks that. But in just about every album I've ever had has been about 50-50 songs I've written or co-written and other people's songs.