Happy tends to tease with a looming apprehension which threatens to spoil the happy before you even get a chance to sit down and have a taste. But still, I can appreciate happy. It gives you something to compare to when things turn south. Because if things were good that one time, chances are, they'll probably be that way again at some point in the future.
I don't even mind sad. Or angry or frustrated or overwhelmed. Because then, at least, there is a logical explanation for your generally crappy demeanor. At least you have a what feels like a legitimate justification for wallowing, and you maybe learn a lesson somewhere in the muck of it all. Also, from my experience, tribulation seems to bring more inspiration than even the brightest patch of sunlight.
What I do mind is nothingness. Nothing-filled moments with nothing to say, nothing to offer, nothing you'd rather do and nowhere you can think of that you'd rather to be. There are words coming at you from the mouths of people you're sure you care about, and you wonder where they got them from. You realize they'd probably appreciate some sort of response, but you've - got - nothing. And it's nothing that you can out run or even sit down and wait out because: it isn't anything. Though it somehow still covers everything up in a big blanket of an empty, pitted, echoing void.