Well, there's my first orgasm experience and then there's my first masturbation exerience. Let's being with the former.
Sometime in elementary school, probably around 3rd grade (so I was 8-9 years old) I was swimming in our backyard pool like usual. But for the first time ever, I realized that it felt really satisfying to pull down my swimming suit and let the water pump blast water onto my prepubescent cock and balls. I sort of just hung onto the edge of the pool, letting it pound my groin until suddenly it felt really good for a few seconds. I was bummed when I no longer felt satisfied so I swam away. I continued doing this for the rest of the summer.
Now, my first masturbation story. I was in 6th grade. Keep in mind I'd never learned what had been going on in the pool. But anywho, my friends and I were talking during lunch. I'd heard a lot of the other kids at school talking about "being horny" and obviously since I was a clueless kid I didn't know what it meant. So I told my friends out of the blue "I'm horny!!!".
My friend Jon replied "So go masturbate". Confused, I asked, "What does that mean??"
He was kind of frustrated/annoyed and just spat out "It's when you massage your dick!!!"
So I left the lunchroom and went to the bathroom. I locked the stall door and literally massaged my dick with my thumb and index finger on each hand. Nothing was happening. Frustrated, I returned to the lunchroom.
A few days later I explained my predicament to another friend. He just told me, "masturbate by doing this" and then he motioned the masturbating motion to me. So that night while I was taking a bath, I did it. I just shook my dick like I was told.
I was such a dumbass that I didn't even know what I was about to experience, or even that this was sexually related. So the whole time I never associated it with my pool experiences, and I don't even think I was thinking about sex while jerking off. Suddenly, I experienced an orgasm! I remember being really scared but it felt good.
And thats the story on how I developed my masturbation addiction.