In August 2016, a 15-year-old Australian swimmer named Ariarne Titmus watched the Rio Olympics as she prepared to fly to Maui for the Junior Pan Pacific Championships.
Titmus paid special attention to her best events, the 200m, 400m and 800m freestyles. Katie Ledecky swept them, breaking two of her world records.
“I remember watching her races thinking, like, this chick is nuts,” Titmus told NBC Sports in Australia early this year, “She’s just doing stuff that no one’s gonna get near.”
Three years later, Titmus stunned Ledecky at the world championships, chasing down the American in the last 50 meters of the 400m freestyle.