Growing up was exactly like that when I lived in Denmark as a little kid (but once my folks started moving around - new country every three to four years - it was hard to make friends - especially when you didn't speak the language
)
However, my neighborhood right now is VERY MUCH like that. I know about five or six families really well, and know another five reasonably well. In this summer, there's often just driveway "parties" at someone's house - bring some beer and munchies and hang out. When I was working on the mustang, several guys lent me tools without a second though, and helped me. When the car looked at its worst - stripped paint and no fenders, hood, trunk, etc - several of the wives of the neighborhood demanded that I drive them around in it, so they could hoot at the other people in the subdivision. It was a riot!
All the kids are always playing together in the street, and several of my neighbors don't lock their doors. When my neighbors across the street had a lot of crap in their garage, I let them park their son's car in one of my garage ports. The ones across the street are really nice folks, and the mom knows that if they need anything, they can just go in my house and borrow it (they have a key). Actually it was those neighbors who helped me find the body guy who is currently working on the mustang.
A few weeks ago, I ran into one of my neighbors and his son at the shooting range - and let the boy shoot my midlength AR and my SBR.
So now they may build an AR - we're going to talk about it one of these weekends.
The best example was probably when I had first moved in, and didn't know anyone, and was working in the yard, doing landscaping on Easter Sunday. The family across the street sent their son over with a plate with an Easter dinner - ham, potatoes, beans, etc. because they saw me out there by myself.
I love my neighborhood - those places STILL do exist, apparently.