I remember once when I was about 13, I was running laps for PE with my best friend. Who has a larger chest than I do, when a guy in our class started running next to us. After a while he asked 'does it hurt?' and us, being clueless asked what he meant. 'Your breast I mean. Does all that bouncing hurt?' We ran him off with a 'none of your business' remark. But needless to say I made sure to buy a sports bra and a bigger shirt to wear the next week.