A good community can make up for a bad childhood. There may be traumatic experiences in your past which you need counselling to overcome, but solving your past problems doesn't move you into the future - for that you need people, a community. The trust, acceptance and security gained from a 'good' (I'm working on this) community
We each exist in the intersection of a heap of communities - family, work, church, other friends... all of whom don't know each other. It's difficult to reconcile. The seven degrees thesis is that each person is a node, and there is a maximum of seven nodes between any two people, anywhere. In the age of communication and movement, we each have to cope with a larger number of communities than ever before. Difficult again.
A horrible hard thing about not being married is that your basic level of community changes from being one person who you see all the time, to about six people who you see once or twice a week. From one person who you know and trust with your whole life, to half a dozen people who you're afraid of imposing on. And when your basic level of community is The One You Love, everyone else stays at arms length. So when someone annoys you or whatever, you can say "oh well, stuff them, I've got you." But when arms length is as close as you can get, you can't afford to let people slip.
Community bridges cultural gaps, including the generation one. Any community will consist of people who have some core things in common, and a lot of things somewhat or not at all in common. Within a community, some people will lie on the fringes of the age or ethnic norms, and these people will be important contributers of experience and point-of-view. Because a community relates through each other as well as individually, people should be able to understand and accept the attitudes of those culturally furthest from them.