To Beer or Not to Beer

Okay, so most of the time there are little nuances of American vs British culture that can catch me off-guard. For example, learning that pants is not the appropriate word to use for trousers or jeans, because the British connotation of pants refer to underwear. So an innocuous statement about getting the leg of my pants caught in the gears of my bike definitely caused some raised eyebrows.
Anyways... on Saturday night I went to join the Cambridge Union (think debating club with a parlimentary debate chamber that a bunch of old, dead, rich, white guys would feel very at home in, but not exclusive nowadays). The membership gets access to everything that happens there over the course of the coming year... debates, ents (entertainments), bobs (parties), a fairly cheap bar, etc. Well Saturday's ent just happened to be Ben & Jerry's night. Talk about a way to bring people in, gallons of ice cream. And, the precursor to one of the funniest cultural misunderstandings I've seen thus far in my time here. So there was a group of 4 of us grad students sitting eating our ice cream in one of the side rooms. Two of us were Americans, one guy was from Singapore and one was from Australia. So the other American had decided that he was done with eating ice cream for the evening and had moved onto a pint of beer. When he came back with the beer, the Australian asked if he wanted any more ice cream. Ugh, you're probably thinking, not a good combination. Well that's what the American told him, that it didn't sound very good. So the Aussie says, "But I thought that was an American treat, like apple pie, putting ice cream in beer. I swear I've heard of that being big over there." Just imagining this concoction turned my stomach. As he kept describing this supposed American tradition, it finally dawned on me, that he was talking about a root beer float. Not ice cream in beer.
Apparently, root beer is not prevalent at all in the UK (haven't found it anyplace in the month I've been here), nor is it found in Australia. So reading about root beer floats, this guy just decided that was a particular type of beer, like a lager or pilsner or something. So at least, there is now one less Aussie out there who now knows what a root beer float is.