IA on the potential for the characters/stories of the early seasons fuelling fandom in a big way. At the start of a show it is pretty much, here are your characters, here is a 'verse, go play. The tired, worn down Sam and Dean now would hardly recognise the people they were back then because so many doors have been closed/different paths taken and there's less places they can possibly go (emotionally or in terms of choices in their lives). It's not really a universe of possibility any more. I kind of think - hope - that maybe the end of the show could give that hope and growth to the characters. e.g. Dean finally realises he doesn't need to/shouldn't sacrafice himself for Sam all the time, and I think that we will get that, but only at the very end.