It came to me at an early age.
Here's my gaming history for perspective:
Willingly, I did not enter. The gaming life chose me. Playing video games during my "developmental years" (I mean in my pre-teens to teens. My mind being the late bloomer it is was like an ever changing Salvador Dali painting: up until only a few years ago in fact) altered me, and led me on the path to who I am as a gamer & a person.
In response to the question of WHY I started gaming... I don't really know. I did not enter with any intelligent thought or desire, but as time passed my reason for doing it was because I enjoyed it. It was a medium for myself and my friends to interact in: especially for LANs, or slumber-parties. The kids who never had anything interesting going on in their lives could use the game as a way to let themselves go / make conversation, like myself.
As the saturation increased the reasoning for my involvement began to deepen. It was no longer some weekend party with the boys... it was my stress reliever. My escape from reality. A place where only I was a denizen. A way for me to immerse myself in vibrant and desolate realities as I saw fit. This change came as I grew distant from others. It wasn't like I was doing it without protest. Not being a country folk, a delinquent, or a "prep" will exclude you from everything where I live.
I was always a loner, and the lifestyle of all my friends & family were not appealing to me at all. Gaming you could say exacerbated the problem, and enabled my introvertedness. I was the cliche kid who sat at home playing video games like Halo 3 all day instead of going outside... and I don't regret it one bit. I wouldn't give up the experiences I've had gaming for anything.
So there you have it. Give me my A+ already.