The reason you get the adolescent feelings is because people are in fact acting like adolescents, forming cliques. I can feel the "cliquey aura" sometimes, when I walk into a social circle.

That's why people try desperately to fit in and maintain their status. But I'd rather stay true to myself, and do what is comfortable for me. And that's mostly possible in real but scattered friendships. "Groups" tend to get cliquey for whatever reason.