would anyone be so kind as to tell me why the world is so unfair?!

Because you can't have the good, without a little bad

Life is full of up and downs, it's just how it works. Like a calm ocean or mountains. What happened?

It's life. Life is cruel. Life sucks.

Differences
As long as theres differences, it'll be unfair.

I think there really is no reason for the world being unfair. :) It just is. :)