Being american is one of those "unconscious privileage" things. It doesn't mean you are better than anyone else but it does mean that until very recently you get the cool comics, the big movies and TV shows before anyone else. Hell, some of the best known american TV shows have never been shown in the UK at all (I have never seen Gilligan's Island), and the ones that did turn up did so often years after they were first broadcast in the States.
Before comics were confined to specialist shops you could find them at selected newsagents (that's news stands to americans), but you never even knew if you would get to see the same titles two months in a row.
It's all different now. UK comics shops get the same selection as the USA only a day later, and if TV isn't broadcast here fast enough, who cares? We can download it the day after it appears in the US and get it on DVD within six months. Movies can still take a few months to roll around, but the pressure is on to minimise the time lag - at least to get it out before the american DVD release.
Even so, there's a lot of stored up resentment there. So anytime we get to see something before you guys, be it the season finale of Babylon 5, the climactic battle between the Daleks and the Cybermen, or the final race of Oban Star Racers (I know who wins! I know who wins!), I can't resist the urge to rub your faces in it.