I'm killing some time before a scheduled conference call with a World Bank representative about the nonparametric alternative to the Human Development Index we've been developing in the labs.
I'm very depressed.
I'm not on a sugar low, I've had a fulfilling lunch, a full 3/4 liter of yerba mate (which means quite a caffeine jolt). I didn't feel this depressed about thirty minutes ago.
Nothing special happened. It just comes and goes, like a migraine headache. Maybe it's because it really is like a migraine headache, but maybe that's just another misguided theory.
I do know that nothing happened and it just came. And it does, every now and then. There are phases it's rare and there are phases it's common. But it's always out of the blue.