"Tell me something, Dean. When your father gave you an order, didn't you obey?"
so sam hates halloween, because his every day life is a halloween scare fest.
sam has also been doing the naughty with his "thought you were done with that psychic crap" powers. killing demons with his mind and all that. and ok, he has a point: kill the demon without killing the human host BUT, well, even if we didn't know the final outcome (damn you ruby), we still know its a dangerous slippery slope sammy and judging from the origins (radioactive demon-spider bite, ha) it can't be altogether a good thing.
oh dean: neither of these two sammy traits are happy for him. he loves halloween and he hates sammy's tempting of the dark side. no win situation.
but all that aside, because people are dropping like flies, in typical halloween urban legend way, with the help of some super-snazzy hex bags and dean is still having a problem with pretty girl vs. age vs. jail bait and epic candy consumption vs. adorable tummy ache.
lol.
throw in adorable handshake!cas, a stinky angel superior, failure at stopping the seal from breaking (on purpose? dun dun dun) and sammy reverting to his old ways, complete with darkened eyes and occupational nosebleed, and you've got 'it's the great pumpkin sam winchester'. love this ep.