Well, let's hear 'em.
Me, I was 6 years old and my mom took me to go see "Adams Family Values" (hey, I was 6 and she let me see a PG-13 movie, it's her fault!
) and somewhere in the movie they said the word "sex". So I asked her what it was and she said she'd tell me later. So after the movie we were in the grocery store and I asked her again. She got all embarassed but knew she couldn't get out of it this time so she clenched her teeth and whispered under her breath, "It's when a man sticks his penis inside a woman's vagina!" She didn't explain it any further right away, so I just sat there wondering why the hell someone would want to do that...for the longest time I always pictured a man and a woman lying perfectly still with his penis in her vagina, and I didn't get what the point was until sometime later.