As a child in Australia we had Danish backpackers come to stay at our place. I recall taking one set of visitors to the zoo, and specifically to see the Platypus since such an animal seemed too strange to be real. Thing is, the enclosure was closed for maintenance that day ... reinforcing their disbelief :-)
Monotremes (and marsupials) have fascinated me since I was a kid. I love these history of science things just because it’s a good reminder of just how young the science of biology is.