I've been called a pessimist so many times, and for the longest time I argued that I wasn't a pessimist I was a realist, that I didn't see only the worst aspect of the situation, that I didn't lack hope for the future, that I just took everything as it comes, that some things are good, but that some things are also bad, that the situation could always be worse, but that the situation could always be better, that optimism was just as bad as pessimism because it was just as inaccurate a way of viewing the world, that optimists tend to ignore problems which have severe negative effects...
But I don't bother to argue that anymore. If people want to call me a pessimist, that's fine. I don't agree, but so it goes.
Anyway, here's a link to something I like.