Everything in the world is either a potato or not a potato
This is such a comfortable statement if you like set theory. {The set of all potatoes} has a compliment, containing everything that is not potatoes. I would say that an object in potato complement cannot be perturbed into being a potato, therefore the set is closed. I’d also say that the potato can be sufficiently manipulated to the point where it would not be called a potato any longer, so the set of potatoes is an open set (with a closed complement, as we would want). So the boundary values of potato-ness belong to the non-potato set.
In addition, this is the most relevant my username has ever been