Reading about the first time in a link reminded me of my own.
I was about 11 at the time and knew that boys masturbated, but never did it long enough to orgasm. After school when I was home alone I began to play with my penis and got it very hard. It was only about 4 inches long but it throbbed and bounced. So I began to stroke it with my fist closing the hand over the head on the down stroke. After about 10 ninutes of this, I began to tremble all over, the feeling got more intense, and suddenly my penis went into delightful paroxysms that spread to my entire body. I kept stroking until I could't stand it anymore. When I let my penis go, it was apple red, and looked like a fish gasping out of water. The orgasm was dry, and masturbation became the most important event in my day.