Simone Biles is not going to explain herself. Part of this is by design. Part of this is because she simply can’t.

When the gymnastics star is at her best, as she was on Sunday night while winning her record eighth US championship, she feels like she’s in a “fever dream.” It’s not autopilot exactly. It’s more of a vibe. A flow.

It’s in those moments that the doubts that still plague her almost daily even now, a decade into a run of unprecedented excellence, fade away.

There is no thinking. No overanalyzing. No “ twisties.” All of it recedes into the background. Her coach Laurent Landi calls it a skill. Biles, even at 26, won’t go that far. Maybe because she simply doesn’t want to.

She spent a long time, far too long, getting caught up in her head. She’s intent on not doing it this around.

So yeah, she was smiling midway through a floor routine that made almost every other competitor on the floor stop what they were doing to watch and drew a standing ovation from a portion of the sellout SAP Center crowd. No, she can’t explain why. When her coaches told her she’d nailed every tumbling pass, she was clueless.

“It just doesn’t feel real for some reason,” Biles said.

It is. Remarkably.

Ten years ago she was a teenage prodigy who doesn’t remember much from her ascension to the top of her sport. She was always fixated on the next thing. World championships. Team camps. The Olympics.

Now she’s a 26-year-old newlywed determined to enjoy this. For real. Six months ago she wasn’t sure she was all in. Three weeks ago she returned to competition in Chicago feeling as if she was going to “throw up” every time she saluted the judges.

The woman who posted a two-day all-around total of 118.40 this weekend in northern California — four points clear of runner-up Shilese Jones and well ahead of Florida junior Leanne Wong in third place — is not ready to hit fast forward. She won. She’s letting herself be happy this time. That didn’t always happen before.

“We really try to celebrate our success individually and as a team just so that in a couple of years you can remember this,” she said.

She knows that gymnastics won’t last “forever” even if, for her in a way it has.

Peaks aren’t supposed to last this long. Most elite gymnasts at 26 — at least the ones who haven’t retired — are simply hoping to hold on to what they have.

The athlete who became the oldest woman to win a national title since USA Gymnastics began organising the event in 1963 is not interested in that.

Biles’ eight crowns moved her past Alfred Jochim, who won seven between 1925-33 when the Amateur Athletics Union ran the championships and the men’s competition included rope climbing.