I'm going to point out the obvious.

Death.
It really hits your body, your emotion.
That feeling, that knowledge that you're never going to get that back, is possibly the worst feeling in the world because no matter what, it's never coming  back.
Sometimes you do forget it, although it's buried deep within your heart, but when you do remember that loss that feeling consumes you for days until the right amount of laughter has put you back together.
Perhaps if there was one thing I could wish for, it wouldn't be money or looks or love, It would be for the people that I have permanantly lost to come back, raise from the dead and be a physical part of my life again.
It's such a hard thing to say out loud, to verbally anounce that their never coming back. No matter how many times you rehearse it in your head, you can't even sit in a room looking at your reflection alone and anounce that you really miss them, that you can't deal with them not coming back.
This stuff never just affects one person, it's a wave of madness that fills everyone hearts.
It's an awkward subject because you never know who has lost somebody.
It's a touchy subject because people bring it up thinking its better to talk about it,
when in reality it's worse. It's worse remembering that they're gone.
But the most worst part is, that no matter how many people you've permantly lost, no one is ever going to understand what you're going through.
Everybody. EVERYBODY. Has different ways of grieving and feeling and dealing with calamity. Everyones relationship, their feelings towards the lost are different. No matter what, No one, understands how you feel.
They just always feel sorry for you. That's it. Sympathy.