She soaked it all in with a big smile of wonder and delight, accepting the cheers with the grace of the queen she now is. But it wasn't until she finally saw her parents and felt their arms wrapped around her that the magnitude of what she'd accomplished hit.
Johnson won the all-around title at the world gymnastics championships Friday, capping a magnificent, whirlwind year with a performance full of megawatt-powered jumps and smiles. And only 11 months away, the Beijing Olympics.
"They just said, 'I'm so proud of you,' and, 'Enjoy every moment of it because it's real,'" Johnson said, unable to stop smiling. "I just broke down. I started crying. I couldn't stop.
"It's a dream come true. It's a feeling no one can ever replace."
And no one ever will. For ever and ever, her name will be listed right there with the best in the sport: Shawn Johnson, the little girl from Iowa who watched the world championships only four years ago and never imagined that some day, she would stand taller than anyone else.
She finished with 61.875 points, a comfortable 1.25 ahead of Romania's Steliana Nistor. Jade Barbosa of Brazil and last year's champion, Vanessa Ferrari of Italy, tied for third.
Nastia Liukin, who passed on her title as U.S. champion to Johnson last month, was fifth after falling off the beam.
"It's a little disappointing just knowing that, if I didn't have that mistake, I was probably able to place in the top three. So I'm just replaying that over in my mind," Liukin said, tears filling her eyes.
"But I'm really excited for Shawn," Liukin added. "It's great to see someone like that. It's great to know she's on your team, especially with the Olympics coming up."
In the men's all-around earlier Friday, China's Yang Wei won his second straight title despite an ugly fall off the high bar, becoming the first man since 1926 to repeat as champion. Fabian Hambuechen delighted the German fans by winning the silver medal, and Hisashi Mizutori of Japan took the bronze.
Meanwhile, Johnson's victory is the culmination of a journey that took off with a trip to the post office two years ago.
Shortly after Johnson qualified for elite-level gymnastics, her coach, Liang Chow, sent national team coordinator Martha Karolyi a highlight tape. Watch it, Chow said, because this girl can help the U.S. team.
It was a bold move by the young coach - especially considering the U.S. women had been raking in more bling than celebutantes since 2002. But Karolyi liked what she saw, and invited Johnson and Chow to a national team training camp.
"From the first time she showed up at the training camp, the little bubbly girl, I said, 'This girl will be somebody one day,'" Karolyi said. "This is the day when it happened."
Actually, this day has been coming for months now.
Still only 15, Johnson has won everywhere she's gone in the last year. The American Cup. The Pan American Games. The U.S. championships. And now, the ultimate prize, the world championships.
She is only the fourth American woman to win the world crown, joining Shannon Miller, Chellsie Memmel and her idol, Kim Zmeskal.
"Winning the team finals, that was a dream come true. Even being on the team at all was such an honor," Johnson said of the team gold she won two days earlier. "Having the all-around gold with me, it's just amazing. It's just the best feeling."