One of my classmates told me when I was in 4th grade... But I didn't know that's how women got pregnant. I thought she meant it was just something silly that couples do, like making goo-goo eyes at each other.

I didn't grasp that people did it for pleasure or for reproduction until I was a teenager. Up until that point, I thought women had babies out the rear, though I didn't really think much about how they got there in the first place.

I did hear people use the phrase "sleep with" when talking about getting women pregnant, but all I pulled from that was that a man and a woman sleep in the same bed for a while, and the woman gets pregnant.