I think intelligent people are more likely to analyze themselves and end up with a less than desirable result.
Most people don't critique themselves with positive comments. They critique themselves with negative comments. I consider myself a realist, positive comments don't help me. Negative/neutral comments about myself enable me to fix things I perceive as wrong about me.
I would say I'm in a state just before happiness most of the time. I don't really think this is a bad thing. It enables me to be efficient, organized and when necessary lead. People think just because I'm not hoping around with a smile in my face and a song in my heart, I must be angry and depressed.
I'm depressed for different reasons
They say ignorance is bliss, and it really is. How can you be sad if the thought just doesn't' occur to you?
You go through life with required reading and multiple choice tests. You get a 4.0, but don't have the ability to think.
That's probably what makes me cynical. I know people that are book smart, but the thought doesn't occur to them to apply it in life. They leave the knowledge in the classroom and spend there time buying skateboard accessories instead.