ANTWERP, Belgium — The field at the 2013 world gymnastics championships was loaded: Two Olympic gold medalists. Two previous world champions. More than a dozen Olympians.

And one 16-year-old American just starting to make a name for herself.

A first-year senior, Simone Biles arrived at those world championships without much fanfare. She’d won her first title at the U.S. championships two months before, but most of the attention was on those decorated veteran gymnasts.

“I remember how in awe I was because my daughter was competing against (Olympic bronze medalist and 2010 world champion) Aliya Mustafina, Larisa Iordache — these were names I’d heard and known,” Nellie Biles, Biles’ mother, told USA TODAY Sports.

“It was the fact Simone had this opportunity, had this assignment,” Nellie Biles added. “It didn’t matter what Simone did. It was the fact Simone was with these big names. I cannot even tell you how that felt, that my daughter was competing with these big names. It was the best thing.”

The top American, in fact, was expected to be Kyla Ross, a member of the Fierce Five that had won team gold at the London Olympics in 2012. Ross had beaten Biles at a meet in Germany earlier that year — remember this fact for later — and finished a close second at nationals.

Biles and Ross were 1-2 in qualifying, and Ross remembers the all-around final being another tight competition.

“It was really awesome to see. It was back and forth the whole competition,” Ross recalled. “It was cool to see we really pushed each other, and we had a really, really strong showing for the U.S.”

They started on vault, Biles’ best event, and she took the lead. Ross chipped away at it on uneven bars, her best event, then pulled slightly ahead of Biles on balance beam. But not by enough, not with the Americans finishing on floor exercise.

“I remember thinking, `Uh, I know Simone’s going to blow me out of the water,’” Ross said. “Floor exercise was always my weakest event. I never had the (difficulty).”

Ross knew that, but Nellie Biles did not. After watching the first three events, she was just happy her daughter was doing well. Then her husband turned to her and said Biles only needed to score in the low 14s to win.

“He was doing the calculating,” Nellie Biles said. “When my husband said that, I said, `Excuse me?’ He said, `She could win this.’”

She did. Biles posted a 15.233, beating Ross by 0.884 points to win her first world all-around title.

“I cannot tell you how to put words in the feeling that I had when she hit,” Nellie Biles said, her voice catching. “When I look back at times that made me feel so joyful and prideful, that always sticks out as my No. 1. I could cry. That always sticks out in my mind. Even (ahead of) the Olympics. Because this was the first.

“I had expectations at the (2016) Olympics,” she added. "But if you go somewhere and that is not an expectation and that happens, you cannot put words to that. I’m telling you, (2013 worlds) sticks out more.”

Of course everyone knows what’s happened since then. As Biles heads back to Antwerp for another world championships, she’s become arguably the greatest gymnast of all time. She’s won five world all-around titles, most by any woman, and is the most-decorated gymnast, male or female, at the world championships with 25 medals, 19 of them gold.

She’s a four-time Olympic champion, with seven medals total. For those counting, that’s 32 total at worlds and the Olympics, and leaves her one shy of matching Vitaly Scherbo’s record.

Biles also has four skills named after her, two on floor exercise and one each on balance beam and vault. She's expected to get another on vault at these worlds for her Yurchenko double pike.

“I am extremely proud of her accomplishments. But it’s never been a priority — it’s not a priority. Her accomplishments have never been a priority. What is a priority for me is that she’s happy. That she had fun doing that,” Nellie Biles said.

“I love the statistics when I read them. But I couldn’t tell you what they are,” she added, laughing. “We do a bad job of that as a family. My husband is the exception to the rule. … So if I want to fact-check myself, I go to Ron. Or Wikipedia.”

Oh, and that all-around competition Ross won earlier in 2013? It’s the last one Biles has lost.

“Simone’s first-ever U.S. championships as a junior, I’m pretty sure I was in her rotation. I just remember she had so much talent but it was very unrefined,” Ross said. “To see her be able to come out in 2013 and win worlds, it was cool to see her evolution and see how much she had. She’d become much more consistent, more refined, more polished.”

Biles and Ross would lead the U.S. women to the team title the following year and share the all-around medals podium again, with Biles winning her second title and Ross finishing third. Ross retired in 2016 and went on to compete at UCLA.

Now an assistant coach at Arkansas, she, too, will be back in Antwerp for these world championships. It will be the first elite-level meet Ross has been to since she retired.

“It’s definitely going to bring up a lot of emotions,” Ross said, “so I’m really, really excited to watch.”

There will be a lot of emotions for Nellie Biles, too. She knows how hard her daughter works and how much she's had to overcome this last decade.

The revelations of abuse by former team physician Larry Nassar and Biles' fight to hold USA Gymnastics accountable. Her demands for substantive changes to what was a toxic culture. The rising anxiety that caused a case of "the twisties" at the Tokyo Olympics, forcing Biles to withdraw from all but one final. The comebacks and the uncertainty that's gone with them.

She knows, too, the expectations for Biles at these worlds are considerably different than they were 10 years ago.

"I just cannot compare that first one to this one. But it’s still going to be amazing," she said. "It doesn’t matter what the end result is. It’s going to be amazing."

Follow USA TODAY Sports columnist Nancy Armour on social media @nrarmour.