Forty Years is No Time At All

Back when I was reading more extensively in Supernatural fandom, there were a number of Sam fans who argued that Dean's behavior towards Sam was abusive. My opinion on that particular argument is too complicated and muddled and confused for a public LJ post, especially given how sensitive the subject matter is.

However, there is one thing I observed among some of those fans that made me raise my eyebrows.

( Didn't something happen to Dean between S3 and S4? )