I'm disappointed

I know that nothing is private anymore, but some people should keep some things in confidence. I am not the most private person, but some particular things should not be shared with the other people. I share alot, but there is some truth to "If you have nothing nice to say, don't say it all." I know it's naive to think all people can be nice, but I thought I was giving this person a chance, but apparently I was wrong about that person. Actually, someone had warned me about this person's character, or the lack thereof, but I didn't listen, so it's my own fault. I know that I'm being vague here, but I'm sure you can guess what I'm talking about. In light of this, I don't associate with people who have nothing nice to say. I am not completely shocked, but rather I am disappointed.