Eight Years, and My Neighbors Still Look Away

I've lived in the same building for eight years. I see my neighbors every day.
In the elevator. By the mailboxes. In the parking lot.
I say hello. Most of them don't answer. They just turn away, like I'm not there.
Only the older neighbors still say hello back. Everyone else acts like we've never met.
Eight years. I keep wondering what I did wrong. Or if this is just how people are now: strangers who share a wall and never say a word.
I'm about to stop saying hello. Maybe that's how it started for all of them.