So I am not always at ease with pessimistic people like myself. Pessimism does not stem form a lack of confidence in the future: one still hopes that things will get better. Pessimism is about the present: it is the painful awareness that things are far from being the way they should, and that we cannot do anything about it. Of course, if one can do something about it and does not, then he is guilty not of pessimism but of sloth, the worst of all capital sins. But most of the times, we have no control over things, nor do we have any chance of acquiring it in the future. Then, we face the choice of either ignoring reality and living our own lives as if we were unconcerned by it, or accepting the burden of awareness.
Both of these attitudes have positives. Living in oblivion is healthy, and is what most people do. They do not care about how the world functions, on the way things should be in order to improve it. They chose to ignore the intricacies of reality, and devote themselves to enjoying the simple pleasures of life: having fun, or running a family, or a business, or having sex with a variety of partners. These are "the healthy ones". Side to side with these, there are the nerds. By accepting to know in what aspects the world is most rotten, they are in the position of doing good if they get a chance to. We owe them the worlds as it was bequeathed to us, so full of flaws. Nerds become such because they hope to to get over those obstacles that prevent them from enjoying life fully. But they cannot overcome their character, and they soon realize that life cannot give them the same thoughtlessness and happiness that the others enjoy. This is why in my view they turn pessimistic. Pessimism is not much about the world, it is about our inability to change it.