When driving long distance and alone, what do you usually think about?!

When driving long distance and alone, what do you usually think about?

I usually listen to the radio and watch for crazy drivers. If I'm driving a long distance for the purpose of meeting with someone, I sometimes practice what it is I'm going to say to them and all the possible scenarios of their responses. I know it's kind of like talking to myself and answering back...does that mean I'm crazy? =)