Some of us Americans know our elevator numbers are wrong — zero / nilth is the correct ground floor by far! — but that doesn’t mean when you pick up the first apple in a bowl of apples you should rename it to nilth. Counting order is different from Indexing order. One is the order of objects in a list and the other is the offset (2nd floor is two floors up from zero). They are just different things and that is why they sound right in different contexts!

(It’s 2023, and we both are right)