One feels extremely stupid when depressed; personally, I get convinced that I am the stupidest being in creation (or nearly, i haven't got to the level of this Darwin Award nominee yet) and will never make anything of myself.
Point proven, of course, by my utter and total despondence and inability to do any work at all.
And then the brain (yes, mine has a life of its own, i have no control whatsoever over it) tends to go off into a whole set of paranoid fantasies, mainly that everyone else seems to know what to do with themselves and that I am particularly useless. And that my life is boring as hell. Which is also true, since being depressed I cannot be bothered to do anything.
I think i'd better go throw myself in a dustbin. This is pathetic.