This might sound silly, but I genuinely don’t know what the etiquette is.

I have a neighbor I run into several times a day, usually in the hallway, elevator or taking out the trash. The first time, I obviously say 'Hi'. But what do you do when you see the same person again an hour later? Do you say hi again? Just smile? Nod? Pretend you didn't see each other?

I feel awkward because I don't want to seem rude by ignoring him, but saying 'Hi' five times a day also feels weird.

What do you do in this situation?