it didn't even occur to me that people might not know their names

Seriously? I see these damned horses for the first time in life. Not only I don't know their names, but it is hard to distinguish them visually. And I put quite a big probability on the hypothesis that 95% of people whom I personally know are unfamiliar with this as well.

whereas I did think long and hard before going with that as my only example

Couldn't you go with apple, pizza, bicycle, broken watch, pen, or whatever sort of items whose names are known? It would perhaps be too ordinary, but your present choice really makes it harder.