Since I was a kid, I realized I was too shy. I think I was about 6 years old, then. Never gave too much importance to it until some years later.
When I was 12, my peers were beginning to avoid me (some of them were actively ridiculing me, but, since I have a sharp tongue, it didn't really bother me). I think it was because I was somewhat childish, while all of them were trying (but failing) to appear adult at the time.
At 14, I moved to another part of the city and had to transfer to another school. I had already lost my friends from the other school and was expecting things to get better. Unfortunately (and, in retrospect, unsurprisingly), they didn't.
At 16 years, it finally hit me. Suddenly, I knew I wasn't simply shy. I spent the next 3 years wondering if I was crazy or not. Those times shall be known as "Dark Ages" (hey, it's a catchy name). During the Dark Ages, I became depressed and lazy: my grades were falling, I was held back during two years; I didn't want to look for jobs et cetera. I became useless.
In 2009, I got my first job (my mother almost had to drag me to the office). After a terrifying first day, which actually turned out great, I started to recover my self-esteem. A few months later, I was on my second job, where I finally made some friends. Even though I was doing much better, I still didn't know why exactly I was so weird.
Finally, last year, I read about Asperger's Syndrome on TVTropes (of all places) and began to research about it. Finally, I had answers. Actually, I heard about AS way back, in 2007, but didn't pay too much attention back then. Doesn't matter; as they say, all's well that ends well.
Right now, I've gone back to studying and got a related job (which I will begin at May 9th). Things are getting better; I only need to get over the social anxiety I've developed during the "Dark Ages". 