If you look at the fact that you have a roof over your head, food to eat, that you are young and beautiful and live in a peaceful land, then no, you have nothing to be sad about. But the fact is, we are not only a physical body, we have souls too, and sometimes our souls get sick. If you break a leg you don’t just say ‘I have no reason to have a broken leg’ and ignore it; you seek help. It’s the same when your soul gets hurt. Don’t apologize for being sad.