go forward and 60 isn't old. i was looking at the cars in the rear-view mirror and i caught a sight of my eyes for a second. and i thought, wait a second, maybe i could go back. maybe that would be the event that would make me feel strong and powerful again. would define me again. >> what once defined diana was marathon swimming. in the 1970s, she won races and set records worldwide. >> i'm interested in the most outrageously difficult goals that i can think of. i fail lots of times because it's so difficult, but i get wiser and wiser all the time. >> strong, brash, confident, a media darling. in august 1978 at age 28, diana set out to do the most outrageously difficult swim she could imagine, cuba to florida, over a hundred miles in vicious