My secret to bike commuting everyday sounds is a bit different than most. I don't have a car. When my lease came due, I just turned that sucker in and haven't looked back.
One thing I have learned is that my motivations change after commuting. I started out to save money, I continued because I enjoy it and now I like that I'm not polluting the Earth with my efficient bicycle.
Maybe think less and bike more and your own motivation will strike you while riding.