Can someone please try to explain this to me?

I don't have that many friends but the ones I have are great. They all know how much of a dork I am and how annoying I get but they still stick wih me. I can tell them anything and they can tell me anything. I have the BEST friends and I don't know of anyone I would like to replaice them with. I am happy when I am with them. But everywhere else I am quiet and depressed. How can someone with friends like them be depressed 85% of the time? I just don't get it.