The slings and arrows of outrageous fortune

Earlier this year, neurologist David Sacks learned that he has terminal cancer and will be dead within a few months. 
In a recent Radiolab interview, he spoke of the moment of his diagnosis, of his overwhelming sadness at all the things he won't see or do. He says "One or two people have written to me, consoling me, and said, 'well, you know, we all die.'"
From this I can conclude that Oliver Sacks has both cancer and terrible taste in friends. And that his friends are very confused as to the definition of console.
I've seen a rash of articles lately, things not to say to people with infertility, things not to say to people with depression, things not to say to a hot tired farrier, and so forth. And it has made me realize that I am not alone in my penchant for saying exactly the wrong thing in these situations (especially the farrier thing - whew!). 
Thing is, there's no right thing to say when someone tells you something awful. We want to say words that make it better, but there are no such words, and so the things that spill out of our mouths serve only to make people feel trivialized. Generally while I'm casting about for the right thing to say, my mouth goes ahead and says something like "Hey, at least you won't have to live through another Transformers sequel, amiright?" 
A very dear friend died some years back. And I think the most consoling thing anyone could have said to me is something I'd never have the guts to say to someone coping with their own loss. "This never gets better. Oh, one day you'll learn to live around it; one day you'll be able to think of her without all the breath leaving your body. But this pain's with you forever. You will never be quite whole again. The world is forever dimmer, your life is forever poorer." Knowing I'd never forget her, knowing I'd never not miss her, that would have been the most comforting thing back then. 
Oh, and what shouldn't you say to a hot tired farrier? Among other things, "If you would just give each of the dogs a piece of hoof they will get out from under the horse and quit fighting." Good to know.