Optimism vs Pessimism

I've always been quite an optimistic person. I take stupid risks and trust that things will fly. Guess have been turning into more of the opposite lately. Been worrying a lot, and actually, I think it's a good thing. It means that I'm actually thinking about things, planning escape routes and contingency plans. I'm strategising, something I never used to do. Is this called growing up? Ha ha. About time, I suppose. :p