In a way they do, but in another, they're dealing with something you can't understand unless you've suffered depression. They feel the aches, have the apathy, sadness, anger and know they struggle daily to just concentrate enough to function. Some even fail at the functioning part and hide in their own world, which may be watching television, playing video games or just sleeping. They are selfish, but considering how I feel when I don't feel good, I can understand the selfish behavior.