Hey, thanks for all the replies!
Quite honestly, for me, I've found that people who have more life experience are the ones who are mature beyond their age. I'm 24 years old, and I feel a lot older spiritually, if that makes any sense - one of my closest friends is 26, her friends are 29, and I'm becoming slowly immersed into their circle. Don't get me wrong, I love my best friend to death (she's also 24) but I feel as though I'm outgrowing her. I think age, or rather, maturity levels play a part in both friendships and relationships.