The party line on '04 was that it was a result of bad luck, bad habits and being overworked. A distinguishing feature was how seemingly without cause my swims in blue were -- I could never pinpoint why I sometimes felt so empty, or so devoid of energy for the simplest of social interactions. But it was overwhelming, and in part I found my way through it by conscious choice -- surely I wanted to not be so bound up in myself, and I did not want to live as a perpetual recluse. I consider that a personal success, of sorts, in that I found a way to make a perversely resistant thing (my mind) yield just the once for something that was good for it.
The point remains that I treated the cause for this episode as being absent. Just one of those things, an unlucky roll of the die, and so on. I've used it as a warning of what happens when you think and feel too much within -- apparently, my system is highly unstable in the absence of sufficient external intervention. In all, a dark period which to learn from, but not much more.
But lately, I must wonder if an alternate hypothesis is appropriate. Perhaps it was an intuiting of a truth I wasn't capable of fully understanding. Could it have been just that I didn't have the words, the experiences yet to quantify the fundamental bleakness of it all?