My relationship with cynicism has been a rocky one. I spent my teenage years convinced of the following:
1) All people are liars
2) All people (including myself) are stupid
3) All people (including myself) are shit
It wasn't until I got into my twenties that I realized such cynicism and misanthropy was getting me nowhere, and that I had met, over the years, plenty of people who directly refuted these claims.
But then again, I've never been cheated on. I've never been a victim of a crime. I've never been backstabbed or horribly treated by anyone except some "friends" who bullied me in school. I have had little reason to lose faith in humanity, and for some people, I do believe a defense mechanism of cynicism is at the very least understandable.
For now, I press on with optimism about most people. I find that life isn't so dark and gloomy that way.