Down here, knowing your neighbors isn't that... critical, or culturally important as in the States. In the States, since most people want to/live in a suburb, they tend to want the whole thing to look nice, so they meet their neighbors and stuff. I only know the people above me, the Bolkovich family, and I got along very well with the patriarch (so to speak) of the family, Elias. He was a brilliant man who died too soon. I also know the people below me, because they have dogs and... well... dogs are cool XD
No, jk, they're actually really cool people who I actually considered worth knowing.
I think it's different in a city as big as Mexico City... or maybe it's mostly the fact that there are no other kids my age in my apartment.