This. There are lots of bad things in the world that do happen. Maybe more bad then good. You have one life to live and sitting around being depressed or angry about them is just a waste of time.
It's like if you're really, really, really sleepy. You can't just suddenly be super awake. You can take pills or try to push through it, but you just want to sleep - you can't help it.
Depression is crippling just like having a broken leg, it's just that it cripples your mind.