There's a difference between pessimistic and realistic.
It's just a way of venting. I play the big one once in a while knowing there's an extremley good chance that I will lose. But i do it just in case a miracle happens.
When people complain, they do it knowingly, but hope they might have a chance. Getting your hopes up all the time, and dreaming of what you'll do with the money will eventually lead you to a huge crash when you don't win. That's why I like the word realistic so much....lol
Afterall, the odds are astronomical.