Not even just the neighbors and friends - people used to live in large family units with 10+ people per household. This meant a much broader support network if, for example, you got ill and couldn't take care of your kid for awhile.
3 more family members are about to move into my house. No matter how much I tell myself that having a larger household and more social time will be "good for me", and of course having help with childcare will be hugely convenient, I'm really starting to dread the loss of privacy.
Two years ago, my wife and I invited my parents to move into a home with us and our children. I expect to always be glad we did, but it has been challenging in ways we hadn't really anticipated. In particular, it requires a more conscious effort for my wife and I to have time to have conversations between just the two of us.
The help with childcare is great as well as the extra hands for household chores. The biggest advantage (and the trigger for this) is that we get to spend time with my ailing dad in his remaining months or years (and he gets to know his grandkids). It also allows us to own fewer cars (2 cars in a household with 4 adults, versus 1 car for each adult). I do wish I had bought a house with an extra bed/bath, however. Not enough to make it worth moving at this time.
That's just a function of how you (and I) grew up. In many cultures, the norm is that offspring live with their parents until marriage, and in some, even the married couple lives with one set of parents.
This is just a reminder that a lot of the things we find comfortable aren't inherent; they're just a reflection of what the norms where during our formative childhood and early adult years.
It also means you need to help others and sometime take time off work from it. People in age range 16-55 were actually people doing more help then receiving it.
On HN it always sounds like you are only receiving, but actual deal ia you provide until you are really old or sick.