Carrie Underwood Reacts to ‘American Idol’ Audition 20 Years Later [Watch]

It's been 20 years since Carrie Underwood won Season 4 of American Idol. So much has changed, yet so much remains the same, even for the "Before He Cheats" singer.

Ahead of the premiere of a new season — Underwood is a judge for the very first time — the show's official YouTube asked the superstar to watch her original audition.

"On the American Idol website, I saw the map, and it was kind of dotting the outsides of the U.S. and their was St. Louis. I asked my mom, 'how far is St. Louis?'" Underwood recalls.

Her mom was puzzled, responding that Checotah, Okla. — Underwood's hometown — was probably about a seven-hour drive.

The hopeful explained that she really wanted to try out for the reality singing competition, which was still in its infancy in 2005, just four seasons in (Kelly Clarkson won Season 1).

Underwood's mom said back: "If you wanna go, I'll drive."

That was all the "Jesus, Take the Wheel" hitmaker needed to hear, and she jumped in the truck, likely rehearsing all the way.

Underwood admits now that she said to herself, "Oh, it's stupid, what are the chances?"

It turns out, the chances were great, and she ended up in front of the three judges, Randy Jackson, Simon Cowell and Paula Abdul at the time. She struggled to move her hands as she sang, she says now, and stops to comment when, in the throwback video, Cowell cuts her off as she's singing.

"Ok, that was very good," he said, but she recalls thinking, "Why did he cut me off?"

Jackson wanted her to work more on her stage presence, and she quips that 20 years later she's "still working on it."

"It is really amazing to think a few decisions that we can make in life that can completely alter our trajectory," Underwood says, reflecting on that time and who she was back then, just 21 years old when she tried out.

"I grew up on a farm in a really small town ... go try out for American Idol, go all over the world to go on tours and make albums, just so I could buy a farm and go back to the farm and live on a farm."

On Wednesday night (March 5), Underwood and her fellow Idol judges, Luke Bryan and Lionel Richie, stopped by The Tonight Show With Jimmy Fallon to chat more about the upcoming season, which premieres on Sunday (March 9, ABC).

Fallon asked her if she still remembers her audition number. The "Southbound" singer wasted not one second, spouting off with a huge smile, "14887."

"I still have that sticker somewhere. It's like on the outside of a little photo book I made," she admits.

She also still sometimes drives the blue Ford Mustang she bought with her winnings.