If I'm remembering correctly, it was when I was three, and my cool, tall, then-ten-year-old big sister had invited her cool, tall, then-ten-year-old friends over for New Years Eve just to stay down in the basement for hours playing games on the computer (whom we keep in fond memory.)They were playing Doom 3, and I spent the whole time staring at the shooting and the blood getting all over everything, utterly transfixed and desperately begging them for a turn. When they finally relented, I took the controls and sucked at it, of course (remember I was three.) At one point, I managed to remember where the shoot button was in time, and I killed somebody! When all of the big kids started cheering for me, I got so excited and proud of myself I stood up on the chair and crowed (I was quickly shushed so that our parents didn't know their three-year-old kid was learning how to blow people's limbs off with a shotgun.)
Eleven years later, I STILL get embarrassingly engrossed in the game when I graphically kill a guy on a screen by pushing a button.