i did that intentionally as part of a competition i was running (bunch of events, long story, but funny). Everyone thinks they can identify beers, or there are Budweiser drinkers that will talk crap about, say, Coors and swear they won't touch it, piss water, whatever. I got 10 common brand beers and gave everyone small dixie cups of all 10. Told them what the 10 beers were and told them to identify what the 10 dixie cups were (each had a number written on it). Heaviest drinker got 4 out of 10 correct, and I intentionally put a couple 'gimme' ones in there (there was a Sam Adams and a Malt Liquor). The rest were things like bud, corona, miller high life, Heineken, o'Douls, etc.
Guy that drinks the most said Miller Lite is his beer he drinks all the time, and thought the O'Douls was the Miller lite.
You'd THINK you could pick out a Corona, or a non-alcoholic beer, or know what Heineken tastes like, but when presented with all of them, really can't tell them apart that much. Maybe if you had just two, MAYBE. but given more choices, they're really all about the same. Your brain just fills in most of the info, and you suck at it more than you think you do.