Pessimism over optimism ?

Is everyone more pessimistic than optimistic or is it just me? In other words, which is a stronger trait - optimism or pessimism?

I can see the pull of pessimism. It is difficult to bear when the expectations are not met. So as a safe strategy, one might set low expectations to begin with while still hoping for the best.

I can also see a charm in feeling like a victim without actually being a victim, giving a vent to all the frustration within, in the guise of retaliation.