Although I probably had a hand around my fetal penis, I didn't masturbate to orgasm until I was about 14. A kid in the 8th grade lunchroom said something about "whacking off" and made a circle with his thumb and index finger. Up and down he gestured. I waited until a quiet Sunday afternoon when nobody was home. At that time I was still small enough to fit into an old canvas laundry bag, and I wore it over my naked body. The feel of the material stimulated me.