Why is life so unfair?

Seriously, what possible good does it do for people to suffer.  And only humans have this problem.  Animals go through life just fine.  Take a pack of feral dogs for example.  You eat what you find, you don't find you don't eat.  Seems simple enough for me.  But we humans can't do that.  We have to steal what others find.  We take rather that gather for ourselves.  This is why I like dogs more than people.