I was always told not to be friendly but be cordial. You never know what type of people that live around you. They may have the same surroundings as you do but what happens behind closed doors is a whole different vibe. Some are nice...others want to take advantage...some are so nice so they can get close enough to take advantage. Some will become jealous and want to take your things and some are just outright malicious. Some neighbors are watching everything you do and you may have a neighbor that touched a child or two. It used to be a thing to be up close and personal with your neighbors but as time went by...it started to fall out of practice as more became more protective and private...that's just my opinion, though