We are 51 (me) and 58 (DH) and are childless, not by choice, but it's ended up being somewhat of a blessing in disguise as we've been able to retire early and travel -- something we couldn't have done so easily if we'd had children. One thing I've noticed, especially recently, is that we seem to have a lot more in common with younger married-without-children couples than with couples our own age. Partly because younger couples without kids don't talk about their kids (obviously), and partly because we still do active, adventurous, "young" activities -- like cycling, hiking, kayaking, etc. while most people we meet who are our age don't. Even though their kids are out of the nest, so in theory we'd have a lot in common with them, in many cases they are into entirely different pursuits than us -- like playing golf, taking cruises, and other things that just aren't "us". Not so many into hiking or cycling. And certainly very few into our type of traveling. Here in Belize we've been traveling in the country as the locals do -- on local buses and carrying backpacks. Sure don't see many 50-something Americans doing that, but we've run into quite a few 20- and 30-somethings who do.

Anyway, it's all very interesting to me and sometimes makes us feel really different. But really, age is just a number, and it's more about finding interesting, like-minded friends no matter what their ages. One thing we've found as we've gotten older is that we're much more open-minded about having friends of all different ages, if we are like-minded and share some interests.