My mom was on a shaken-baby jury a few years ago, and the defendent (the father) was crying on the stand swearing he didn't know he could hurt the baby by shaking it. She was sympathetic. She teachers high school, he was seventeen, and she knows her students have no awareness of a lot of stuff they see regularly on TV. It just passes them by. It's like when you watch an old black-and-white movie that you saw all the time on TNT as a kid and realize, holy cow, this movie is full of sex and racism, and that character's an antisemitic Jewish stereotype. As a kid, you missed it all.

Ten years from now, they'll watch one of those "Never never never shake a baby" PSAs and realize, "Hey, that's about not shaking a baby! I thought it was just pictures of cute babies." I kid you not. A lot of kids sit through two weeks of sex ed for five straight years and then are totally shocked when their girlfriend gets pregnant after unprotected sex. And then they're seventeen years old with a seventeen-year-old's impulse control, and they're taking care of a baby, and ....