I can clearly remember my very first orgasm, and the circumstances that brought it about.
It began when I was in my science class at school when I was 11. I found a paper meant for a class of older kids, which described the basics of sexual intercourse. As I remember it didn't go into too much detail, but it certainly impressed me at that age. I probably knew about sex before then, but I don't recall thinking too much about it.
Anyway, I forgot all about what I'd read and got on with my school day. When I got home and settled into my evening, I found myself thinking about my discovery earlier that day. I was in my parents' room at the time, for some reason I can no longer remember (I was alone in the house), and naughty me got an idea.
I opened my trousers and pulled out my cock, then I knelt down beside my parents' bed. I was very scientific about it; I thought that the gap between the mattress and the base of the bed could represent the woman.
So I lifted up the edge of the mattress a little and popped my stiff little penis in there. Then I began pushing in and out, as the paper had said (I found I needed to push down the mattress with my hand to get the best effect). As soon as I started moving I was filled with the most amazing sensations I had ever felt, and I can remember thinking 'So THIS is what it's like!'
It took maybe four or five thrusts before my crotch seemed to explode as I had the most incredible orgasm I have ever had! Even now, some twenty years later, no orgasm 'cums' close to that first time. It was a dry climax, which given the circumstances was probably just as well.
It made such an impression on me that I did it in bed that night, realising that my hand would do just as well or better.
And I've been doing it almost daily ever since!