seriously

Okay, well I have realized that I thought I had some really good friends. I found out that is not the case. Certain people only call or send me messages when they need something. They weren't there for me when I needed them, yet, they expect me to drop everything when they need me. There situation is always devastatingly bad (even though it isn't really) and they never want to look at the plus side to anything. I just don't understand. I really don't. Why is it that they get all sad and depressed when it comes to things that they should be thankful for. If someone gets hurt, be glad they aren't dead. Why must it all be so damn sad and depressing. Why can't some people look at the silver lining. I just don't understand it at all. They live their life every day in the whole what if scenerio. What do you gain from that? Why must you turn everything, EVERYTHING, bad???