[dclowd9901]

I blame it on the surprisingly structural cleverness of a bicycle. Opposing triangles probably isn’t the first thing most people think of when they think of a bicycle (vs two wheels and some handlebars)

[gwern]

They also can't draw pennies, the letter 'g' with the loop, and so on (https://www.gwern.net/docs/psychology/illusion-of-depth/inde...). Bicycles may be clever, but the shallowness of mental representation is real.