What is most evident at swim meets, in fact, is exactly what is not happening, Ledecky’s Zen-like way of avoiding stress. She is not about to be so rude as to ignore the question that is asked of her over and over, but in her off time—in the car on the way home from morning practice, anyway—Ledecky seems perplexed. “People always ask, ‘Don’t you feel the pressure?’ ” She shakes her head and rolls her eyes, long-limbed and friendly in person, with nut-brown hair and a wide smile. “And I really don’t feel it. I’ve just always set goals. When I was a kid, I would write them down, and I would work toward them, and that’s still pretty much what I do. In 2013, I sat down with my coach, and my goals are set through 2016, though since then a few things have been added.”

“You used to put them up in your room,” her mom says from the driver’s seat.

“They’re just not in my room now,” Ledecky says. “I have a reminder somewhere, but I am not going to tell where.”

Her fans (and they are legion, and they are swimming in high school pools the world over) see her as the poster woman for optimistic self-discipline, with 20 to 25 hours per week in the pool and about five hours of work in the gym. An example of this work ethic: In 2014, she tells me, achieving her world-record-setting mile speed was not only not easy but painful—she drove herself very hard to win. “That hurt,” she says. She kept pushing herself, though. “Now my speed from 2014 becomes my easy speed.”

This is the extent of her secret weaponry: a devotion to practice, to superhuman goals achieved with a low-key, family-supported routine, one that involves watching CNN after dinner and maybe a little on-demand SNL while doing all the big reading for school on the weekend, so she can get to bed by nine-thirty. “She’s extraordinarily ordinary in some respects,” says her older brother, Michael, 21, a senior at Harvard and an editor for the Crimson. “I mean, the way she carries herself, the way she goes about things—there’s no drama or anything like that. She’s just always very dialed-in and doesn’t let the extraneous things, whether it’s expectations or anything else, get in her way.” Katie credits the dozens of Stratego games she played against Michael in London before her swims with preparing her mentally for her Olympic gold, and cites his diligence as her inspiration. “I’ve always looked up to my brother, for how hard he works,” she says. “I started swimming with him, and we had a lot of fun.”

I don’t know if she has any weaknesses. If she does, we haven’t seen them yet Missy Franklin

Her poolside rep is that of the teammate who sticks around for other people’s races; even a little before 7:00 a.m., she is impressively upbeat. On the quick drive home to the Ledeckys’ cozy Colonial in Bethesda, there’s only time to discuss the barest of the day’s logistics because when her mother pulls into the driveway, Katie is up the stairs and into bed, to sleep for an hour before her classes at Georgetown University. Her father, an attorney, is in the kitchen. “She doesn’t have a lot of time on land,” he says.