I almost fell off my chair reading this one so much of it was just like my own masturbation history.
I too learned how to masturbate at about age two or three. (I know the age because we moved into town when I was three and I remember being upset not having my navy blue blanket that I masturbated with.) Sometimes I did it by lying on my stomach humping a bit of wadded up blanket but mostly I did it like that author of this story. I would lie on my stomach, make a fist with my hand (right, I think), place in on the palm of my open left hand and lie on so that the fingers of my fist pressed against the underside of my penis. I'd then twist my fist back and forth so it would rub against my penis. I always did this clothed or at least with my underwear on. It never occurred to me to do it nude. Unlike that author, I did always have an erection. I had no idea what I was doing except it felt good and was something to do at naptime before I dozed off to sleep so I may have done it as much as five or six times a week. I never experienced a dry orgasm. I'm not sure if I could have if I'd known to keep going. I didn't have to pee afterwards but I do remember one time when I was five trying to tell my best friend Allan about it and I described it as feeling like I had to pee. I don't know if it was in impending orgasm or just that I had an erection while doing it and often had an erection when I had to pee really bad and associated the two feelings. I didn't realize anyone else did this or did it the 'regular' way. One time I did try to show my friend Allan but my mom shooed us outside to play. I don't know if she was gently squelching what would have been sex play or just didn't want us messing up the freshly made bed.
I kept up the fist twisting method right up through puberty, which struck a few months after I turned 13. I remember vividly how I suddenly started getting very hard erections every night before I went to sleep and waking up with them every morning. I had no pubic hair yet and couldn't have been over two or three inches long. I never thought of measuring it. I could not stop myself from rolling over on my stomach and starting the fist rocking. It felt really good but the compulsion to do it scared me but try as I might I couldn't not do it. Some weeks/months later, one Saturday morning I was going at it, straining harder and harder because it felt so good when all at once I felt something pull down in my nuts like a switch flipped or a bow string twanged, I got hot all over I pushed really hard and felt something go out of my penis. This was my first orgasm. When it was over I rose up and pulled my briefs down to see what had happened and there was a drop of white stuff on the slit of my penis. I don't remember knowing what it was but for some reason it didn't worry me.
Once I had my first orgasm I had to keep going till I came so I was doing it twice, sometimes three times a day. At first it was only a drop or two of semen but then it got to be enough to make a stain on my white briefs. I tried stopping short of orgasm and holding it in long enough to get my briefs down so I could catch it on some tissue but most times I was unsuccessful and pretty soon all my briefs had yellowish stains on the front. By then, like the author, the fist rocking method didn't work any more. I think my penis had grown bigger than my four fingers so I went exclusively with the blanket humping method. There was still the stain and clean up problem. I don't know why I didn't think of using a rag or sock but I didn't.
It was over a year later that I learned the normal fist method. I was doing sex research in the local library. Hey, no porn in small town America in the mid 1960's and no one to talk about it with either. I came across a description of how 'most boys' masturbated. I went home and tried it. Since there were no pictures in the book I took the description of 'make a fist and move it up and down' to mean make a fist and rub your closed fist against the underside of your penis sort of like I used to do lying on the bed. I tried it and it did next to nothing. Next day it occurred to me that I should grip my penis and make a fist around it. I tried it and it worked just fine. That solved both the mess problem and freed me to masturbate in places other than my bed. Although I still did the blanket humping because it felt better most of the time I masturbated in the 'regular' way.
Thanks for letting me contribute. Now that I've done it once maybe I'll tell some more of my masturbation history.