Hrm, well. I feel like I'm a little bit of both, since I do have a lot of confidence in myself and what I'm capable of but sometimes when I just can't get something right or something in my personal life is just screwed up (which I've had plenty of times), I kind of take it out on other people. However, when I do feel pessimistic, I don't actually want to rain down on someone's parade, but I think I may have sometimes done it on accident or unintentionally.

I'm usually more optimistic though. I've learned that I just have to be mature and deal with bullshit, and overall, I feel good that I was just able to handle things in a healthy, calm, and maybe even kind way. I've recently been a lot more optimistic because I've been getting good grades, winning skate competitions, getting a few more clients than usual, and just being able to make it through each day especially when I made it through in an optimistic attitude just makes me even more optimistic.

I think I also feel the most optimistic when it comes to contests, competitions, and/or challenges. They give me something to do, and if I think I can actually do it and be able to give full potential and determination, I feel very optimistic. And even afterward, if some douchebag wants to say some shit or be stupid, I'm even more optimistic because I feel pumped and proud that I was able to make something of myself and even prouder that I can just ignore the moron and move on and just have fun.
and this is just my opinion, but I like to think that fun is the sole foundation of optimism. :p