It's been nearly two decades since Carrie Underwood heard her named called as the 2005 winner of American Idol. Of all the mementos she has kept since that exhilarating day, her journal is among the most treasured.

"Please enjoy a page from the journal of a 22-year-old farm girl who just had the most incredible night," Underwood, now 39, shares on Instagram. "I still feel the excitement through the pages! Happy anniversary to me and a forever 'thank you' to all who voted! ☺️"

Next to the caption is Underwood's firsthand account of that unforgettable night, written soon after.

"It came down to the final moment," she wrote. "Ryan had the gold card in his hand. Oh yeah, I forgot to mention that they presented us with keys to 2 identical red convertible 2005 Mustangs! How cool is that?"

"Anyways, back to the story," she adds, getting back on track. "Big moment. I took one more look at the amazing crowd and let it sink in for a few seconds. Ryan said something like 'And your 2005 American Idol is...' My heart heart beat fast and I closed my eyes. CARRIE UNDERWOOD!!!"

Underwood recounts immediately crying as the other contestants rushed out to hug her. Then she had to sing "Inside Your Heaven," which she says she "blubbered through."

The win was so big, it might have even overshadowed Garth Brooks proposing to Trisha Yearwood, which happened that same night in the spring of 2005. Of course, the Idol finale was televised nationally, which gave it a leg up in the headlines. Had social media been more prevalent in the early 2000s, perhaps the big question would have gained more ground.

Seventeen years later and the "Ghost Story" singer is gearing up to release her ninth studio album, Denim & Rhinestones, which she will promote with a massive tour beginning Oct. 15. Jimmie Allen will join Underwood on the trek, which will run through March 17, 2023.

Underwood also recently revealed that her Las Vegas residency, Reflection, will continue with more dates next year.

PICTURES: See Inside Carrie Underwood's Beautiful Post-'American Idol' Home

Carrie Underwood invested her money wisely after winning American Idol in 2005. One of her first big purchases was a 3,099-square-foot home in the well-to-do Nashville suburb of Franklin, Tenn. Underwood paid $384,000 for a luxurious 3-bedroom, 3.5-bathroom stone and stucco home in a private gated community.

The house features a library, a vaulted ceiling and lovely amenities throughout, but while it's very nice, it's certainly not the kind of home you'd picture for a budding country superstar. Underwood wound up being a huge success right out of the gate with her debut album, Some Hearts, and she sold the home in Franklin for $372,500 in 2007, when she purchased the Brentwood mansion that she would later share with her husband, Mike Fisher.