Hindsight is always 20/20
First of all, 20/15 is the best visual rating. I don't know what people say 20/20, as that's an expected average which doesn't imply very good vision, merely acceptable vision.
Ah, you must be unfamiliar with the phrase..and standard optometry for that matter as 20/15 isn't the best visual rating...20/.000∞ is (obviously).