When a 12-year-old Lani Pallister got the autograph of the greatest female swimmer, Katie Ledecky wrote "Dream big''.
Pallister did, but endured several nightmares before finally breaking a world record of American legend Ledecky.
The Sydney-born Pallister is the first swimmer to better a Ledecky world record in the 800m freestyle, setting a short-course benchmark at a World Cup meet in Canada on Sunday.