Bullying
I was always the new kid (17 schools) and, in elementary schools, always the kid getting beaned in the head during dodgeball (among other forms of remorseless bullying). I still won't participate in sports that involve balls flying through the air. (It's ice-skating and horseback riding for me!)
When a former coworker started telling breast jokes, I told him -- "look, jackass. they might be funny to you, but having been the butt of those jokes for the past 25 years I'm here to tell you they're not funny to me. wait till i leave the room!" Repeat every few months.
It's a huge problem and I don't know what to do about it - but then, I don't have kids. Just ventin'.