Your outlook on things directly affects your mood or your indifference, and vice-versa. Basically, your optimism is directly proportional to how much you smile, and vice-versa. Do you look cheerful when you're sitting in the classroom? When you're getting your teeth worked on? When you're asleep? In a way, that's a good thing, and in another way, it might be slightly scary. Due to my boredom, I've tried to arrange the exact frequencies of how often you smile to the correct description. Feel free to correct me if I got something wrong, or if you know where you place on the list.

100% - No doubt about it, you have a syndrome. See a doctor.
90-99% - When you're trapped inside a dark pit, buried underground, with the dirt closing in on you, which is slowly being flooded by water, directly next to a swarm of mad bees, the exact thing that goes through your mind is "Well, at least I won't get sunburned."
80-89% - Only truly devastating situations have any impact at all to you, and you either comfort people very much with one quick glance or disturb them by "oversmiling". The latter rarely happens, though.
70-79% - You can basically take anybody's bad day and show them the light of it. And in the case of your own bad days, you mask it with cool little emoticons. "My dad's plane got cancelled and he's stuck in Norway for another month. ^_^"
50-69% - This is all a kind of "neutral-happy" zone. No matter what, though, you're not sad. You're most likely one of the lucky ones who managed to avoid that "angst" phase which started around seventh grade. You're not a Cheshire cat, but you're pretty close.
40-49% - Your most common reaction to bad news is "Ahh, so what?" However, unlike the higher percentages, the really bad stuff hits you hard. You do endure, though, and realize that you can't be gloomy forever.
30-39% - Now, I'm not exactly sure what to name this area. My first idea would be "mood-swingy", but that's not exactly the point I'm trying to make here. The way you feel will vary depending on your previous situations, or something. Hopefully, you know if you fit here.
25-29% - You're slightly above the "neutral zone", but the odds seem to be in your favor. You might try to predict when bad events will happen so that you don't react so badly when they actually arrive. No, that's not pessimism.
21-24% - Where the majority of people are. The "neutral zone", as I like to call it. Good things happen, and bad things happen. Sometimes you're in a good enough mood to smile; sometimes you warn people in advance to stay away from you. Either way, the majority of your day is usually symbolized by a blank expression.
16-20% - You were in a bleak situation to start with. Occasional moments of cheerfulness come, and you basically seem like all the other "neutral" people, with just a little bit of shadowing the truth.
11-15% - This is pessimism. This is also about where I fit in into this whole thing. It isn't as low as you may think. Sometimes you may be too tired to be cheerful. Sometimes nothing exciting happens. A lot of days seem like nothing to you. If it isn't important, you probably forgot if something happened. Then come the days when a black cloud floats over your mind, nearly forcing yourself into that dark pit. You better have at least one 70% or higher in your life, or else you could have dipped even lower.
6-10% - A constant nameless dread is always in your future. You may try to be happy, but it doesn't last very long. In your mind, optimists are crazy. Most goths go somewhere around here.
1-5% - Eek. Bitterness, anger, confusion, depression, angst, frustration, and maybe those one or two rare moments or perkiness where you find a quarter on the ground. Nearly nobody can help you because you've locked yourself here. Throw up that key you ate and escape from here as soon as possible, unless you plan to take over the world or something. The chances of that happening aren't very good, ya know.
0% - You literally have no soul. You didn't smile when you were a kid, or when you were reading this. Humor has no effect on you. You can't be cheered up. You might as well be a robot, because even though they don't have emotions, that's better than what you're putting yourself through.

Okay.