I probably won't retire (even if, by some odd chance I have an opportunity to do so). So I can't really imagine myself living in a retirement community. It's the kind of self-imposed segregation what would have me seeing only the faces of those as old as me, or older. The kids I see on a daily basis are often a reminder of who I was, and the motivation for the best things I've ever done with my life (admittedly, there are precious few).
That's why I find it particularly irritating when I hear the retired complain about paying taxes for things like schools, parks, or pretty much anything that benefits the young. Their rationale is that they've raised their children, and shouldn't have to spend money on everyone else's. The flaws in that argument are self-evident.
The irony is that these are the same people that wax nostalgic about the good old days when we all cared for each other, and enjoyed a sense of community. (I have a feeling this was only true if you were white, Christian, and well-off). The definition of a community, whether it's a neighborhood, or a nation, is a group of people working together for the common good -- to achieve together what we cannot alone. Sometimes this means doing things that don't benefit us directly. Most understand that it's a small price to pay in the scheme of things.
The "I've got mine, you get yours" type of social darwinism has always been around. But, until recently, has usually been associated with the ignoble, petty, cruel parts of our nature. It's a sentiment that those like Ayn Rand and the far christian right have attempted to legitimize using pseudo-philosophical twaddle, perverse interpretations of scripture, and junk science.
It's a darkness that, unfortunately, lies within all of us. It shouldn't become more pronounced as we get older. As much as I am able, I choose to be a part of everything until it's time to go.