This is in reference to the 4.10 ep, Heaven and Hell, where Dean gives up the goods at the end and tells Sam the reasons why he doesn’t want to talk about hell. We find out the awful truth: that in order to stop the pain, Dean got up off the rack and became a torturer himself.
I realized I want to know WTF happened after 30 years that made Dean suddenly change his mind. I mean you don't go through 30 years of torture and then wake up one day and say screw this, do you? (I’m pretty sure Sam feels the same, but he’s being a Good Brother and giving Dean his space. For now, anyway.)
Maybe, after 30 years, maybe he hit his breaking point, maybe he got tired of Alistar coming by EVERY single day and just hit his limit.
When Dean said, at the end of Wishful Thinking, “…the things I did, the things I saw…” I instantly thought/figured/hoped that there was non-con between Dean and Alistar, because I’m whacked that way, and I kind of thought THAT would be the reason Dean broke. Not that he suddenly gave up one day. Or maybe Hell used Sam in some way, something that Dean thought was Sam.
What's most interesting to me is the fact that fanfic never considered that Dean could be broken, that he would make the choice he did as presented in canon. At least not the fanfic I’ve read. (I would be willing to be shown the error of my ways, however.)
I'd love to know what other people think!