Depends on an issue that's out of my control and out of reach of my influence, depends on what I get involved in, depends on my experience with a particular matter at-hand... I don't think people should label each other as pessimists or optimists. If you're exhibiting behavior consistently exclusive to one of those traits, you may need to examine yourself or get examined. Use logic, not hope and dismay.
Are you ready for far below freezing temperatures coming soon?