Yeah, it’s not easy to come up with something that is absolute like that, and also make it immediately understandable to a wide audience without needing to explain it.

For example I can say “an anarchist country is like saying an unarmed interstellar spaceship”, a lot of people wouldn’t know that it’s actually impossible to have an unarmed interstellar spaceship, so this defeats the purpose of the comparison because it requires an additional explanation.

I can’t think of any example right now that is absolute and that is also ubiquitous knowledge to be immediately understood without relying of specialised interest knowledge or explanation…