Munchausens Syndrome

Does anybody know when it is appropriate to have a midlife crisis? See on Monday, I'll be 34, and assuming the biblical lifespan of three score and ten years, that means that I'm heading quite rapidly to midlife (note the absense of the term "middle age"...)

Can I have a two year long midlife crisis starting on Monday? Or do I have to wait until I am older? I don't want to trade my girlfriend in for a younger model, but I wouldn't mind an excuse (or the money) for a sports car.