Within one minute of meeting my co-worker Jim on my first day of work, I knew that I had found a kindred spirit. It wasn't anything he said; it was a gut feeling I had. This was years before I knew anything about autism and AS.
Growing up, he hated loud noises, he was clumsy, he used to sit in his room and people watch for hours and hours. There was an occasion when his mother couldn't find him and sent a search party out looking for him. It turns out that he was hiding behind the drapes for hours and didn't respond to his name.
Schoolwork came really easy to him, yet he had trouble relating to his peers. He had a tendency to make obscure jokes about science that others didn't find amusing. He was more-or-less a loner until 8th grade, when he fell in with the other "social rejects" and slowly learned how to interact. (For me, it was 10th grade.)
To this day, Jim still tells the obscure subject-matter-related jokes, he stims (though many people do this), and I would say has different eye contact than most (although I don't find it uncomfortable). He walks fast and really enjoys making others happy, two traits that appear to be common among Aspies (I'm no exception). We didn't get into obsessions, but I suspect he has some of those tendencies as well.
We both discussed the importance of finding a group of peers where we could just be ourselves and be accepted for our quirks, and how important it was to have parents who didn't try to make us be people we weren't. I never quite realized how important that was until I came here. I'm nearly certain that neither of us would be as healthy as we are today if we didn't have these two things in our lives. I bet that this is true for anyone, not just Aspies.
He has no idea he might be autistic.