The in thing since the ancient days of Dale Carnegie has been positive thinking.
Nothing takes the wind out of my sails more consistently than hearing reminders of the vital importance of constant positivism. I've never believed that. There's more to life than pretending you're happy when you are actually urinated off about something that you feel strongly about.
Ronni, in her wonderful blog, Time Goes By has a good one entitled "Grumpy is Good For You." I think you will get a kick out of it!