There is a latent and systemic age-ism that cuts a wide swath through most of American society. Everywhere you go you see it. The park, the mall, the beach, schools, everywhere. People socialize with others in their own age strata only. We are marketed to in this way, we are cross-sectionalized this way, and we have bought into it.
In other countries you see cross-generational socializing, especially in the context of families. But here in the US, toddlers hang out with other toddlers, adolescents with other adolescents, teenagers with teenagers, and so on all the way up to our most senior of citizens. (Which may in part explain the reason why the elderly have less friends - as we get older and more of our peers pass away, we start to age out of the ability to have a large number of friendships because there aren't as many of our peers around to have friendships with).
Does anyone have friends - actual friends, not just people who you are somehow required to spend time with - but actual friends, who are more than 10 or 15 years older or younger?