If imperial units are so human friendly, why do I have to look them up every time I need to convert between them? I do it occasionally and pretty much the only

If imperial units are so human friendly, why do I have to look them up every time I need to convert between them? I do it occasionally and pretty much the only one I remember is 1 feet = 12 inches. I think the parent is right that it has mostly to do with what you are used to.