I think that's pretty funny. I see people complain all the time on here about it too but I think there are more variables than just what the stickers say. I say most people don't admit to how hard they drive their cars. I hit redline in first and second multiple times and still get over my epa estimated in all my vehicles I drive. I do tons of highway miles though.
I like using my Subaru as an example for this: on the highway I average 28 mpg at 65mph and about 26mpg at about 75 mph. Epa estimate is 25 highway. In the city epa says 19mpg I've never gotten under 24 doing all city driving with really short commutes( around 1 mile each way 4 times a day when I was in college). My worst tank was 22mpg driving side roads really driving hard.
2003 Ford Focus ZX3(Brokus) - old and still busted
2007 Subaru Impreza 2.5i - current DD