I have vivid memories of masturbating for years! I have written about a few here.
1) When I was about 5 or 6, I had a friend that I would play with. One day he asked if I would take my pants off if he did (I think he was probably about 8 or so?). Anyway, we both did and we compared each other. We called our 'parts' the 'dinkery' and the 'bumery'. I remember him asking to rub my penis (which I let him do if I could do him). We both got erect and he tried to get his penis inside of me ... unsuccessfully!
2) When I was a cub (young boy scout), we went to camp. One afternoon a bunch of us were in our tent, and someone showed us if you rubbed the tip of your penis on the sleeping bag it would feel good. I remember a whole bunch of us walking aroud the tent with our cub hats hanging from our penises!
3) My sister was eight years older than I. I remember sneaking up to her room one evening after I was supposed to be in bed to wait for her to come back to her room after a bath. She went to her room with a towel wrapped around her. She MOSTLY closed her bedroom door. I snuck up to it and watched as it slowly loosened and dropped - boom - I got to see her tits! Small and pointy but they looked great to me. I think I got an erection, but, did not really know what to do with it.
4). My first ejaculation occurred when I was home sick with a cold. I was lying in bed and bored. I started to play with my penis to make myself feel better. All of a sudden - a massive orgasm and semen all over. I thought it was something to do with my cold. I also thought I might pass out. So a couple of hours later when I tried it again, I made sure it would not look to obvious what I had been doing in case I got found. I think I just opened the fly in my PJ bottoms so my penis would poke out.
I've been enjoying myself ever since. Probably 5 or 6 times a week!