I like to take mine to the gorilla exhibit and tell them that's what we used to look like - LOL.
Try going to the Air and Space museum and hear parents give their kids wrong info there. As a space enthusiast I often want to jump in but don't. ;)
Sometimes though people are just not observant. Every display in any museum I have been in has had printed info nearby to explain what you are looking at. Though there was the time at the Saturn 5 building at the Kennedy Space Center when I heard a guy so dense I couldn't believe it. We had all just come from the theater where they had a great movie full of info about the Saturn 5 rocket and its magnificent history. Then the doors open and 100s of people stream out into the museum where a real Saturn 5 is on display. A little kid asks the father what this rocket did. The guy replied, "umm, I dunno." Brilliant!