Misery loves company

I hate the feeling of disappointment. It sucks like a gay man; well and hard. I truly, truly detest the whole notion of expectations. You expect something, even though you tell yourself over a million times that it isn't happening, and yet somewhere in your tiny, tiny brain, something called "hope", I believe, makes you still think that your expectations will be met. You could say that I hate hoping, but yes, yes I do.
I forgot what book it was, but I was reading one and in it's pages was an "Equation to Happiness", and it went something like;
less expectations=more happiness
The whole idea about it was that the less you expected the more happiness you would get because you'd be surprised every time something good happened to you, because you weren't expecting it.
If, in theory, this is correct, then what about the bad things? The bad things that you don't expect seem so much more worse than the ones you're prepared for.

Eg. A friend went to a funeral and was talking as if she had gone to get a haircut.
"Who's funeral was it, if you don't mind?"
"My Granddad's."
"Oh.......I'm sorry."
"Oh, no, it's okay. He's been sick for ages so we were all expecting it."

SO NOW, the true equation to happiness is;
expect the bad shit, don't expect anything good to happen to you and you will be happy, i.e. become a pessimist.
I don't really understand this, because I am a very, very pessimistic kind of human, so in theory I should be the happiest thing since a powerball winner. But I'm not.
In theory, but not in practice, aye?

And here I am, still feeling disappointed and wanting to hurt something D: