I've discussed this a lot in real world in a different field: apartment floors. In Japan (where I live) they are 1-indexed, where the floor on the ground is num

I've discussed this a lot in real world in a different field: apartment floors. In Japan (where I live) they are 1-indexed, where the floor on the ground is number 1, while in Spain (where I am from) they are 0-indexed, where the floor on the ground is number 0. Both have inconsistencies, like in Spain you might have a "middle ground" (entresuelo) which is neither 0 nor 1, but sits between, and is normally commercial or non-livable, reserving the 1 to the first floor where people live. I like that system better though because it usually goes 1 => 0 => -1 (underground), while in Japan you go 2 => 1 => -1, so I feel like it's missing a floor. You could justify it though as 0 being the ground line, so +1 is "the first above the floor and -1 is "the first below the floor", but I still prefer having each floor to be a natural consecutive number.