Avengilante wrote:
You may feel more mature when younger, set apart from your peer group socially and often concerned with specific subjects of interest which you learn about in great detail, unlike others your age.
As you become older though, you may find the opposite becomes true, in that as others your age start to develop careers and have families, a lot of the things that seem to come naturally to them as adults still seem like big grown-up chores that you're never quite adequate at. That's the Executive Function part of the brain that for those with AS and HFA pretty much stops developing beyond adolescence. So you may find that as you get older, you start to feel significantly less mature than your peers.
This is exactly how I feel. Catching up with former friends on Facebook really puts into perspective how immature I am for my age. A lot of them are in relationships or are already married. I know at least one who has children. They're into mature things such as drinking alcohol and fashion. I feel like my mental growth has been stunted (or at least very delayed). I quit being interested in cartoons only less than a year ago, and I'm only now getting into make-up, movies and celebrities. Those are things I should have been getting into when I was still a teenager.
But even though this "immature" aspect of me makes me feel a little embarrassed, I do try to accept it as part of who I am. I even try to embrace it, because hey, why fight it? Life's too short to pretend to be someone you're not.

Besides, my mom has told me: "You've grown a lot within the past couple of years. But even if you never mature beyond this point, I'm perfectly happy with it."