We used to play Doom in kindergarten. Pretty sure that wouldn't fly today, it was finally removed from the 1 PC available after parents started complaining of children having nightmares.
I was hooked by the time I was in kindergarten. I distinctly remember being bummed out when a friend didn't have video games and we had to play with toys instead.
It was the Master System version, that came installed with the console. I never had any other MS game, we just rented them. Anyway, I wasn't hooked by video games until I had a SNES some years later.