FLASHBACK: Carrie Underwood and Kelly Clarkson Before 'American Idol' Changed Their Lives Forever

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As American Idol's last contestants ever await their fate, ET is looking back at two of the show's greatest champions.

Carrie Underwood, arguably the program's most successful winner, surely had no idea what was in store for her in the summer of 2004, when she was a nervous farm girl from rural Oklahoma just waiting for her big chance.

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"I'm a T-shirt and jeans kind of girl, so I'm ready for someone to get a hold of me and tell me what to wear and what to do," Underwood told ET during our first interview with her in 2005.

Cut to 2007, when ET chatted with Underwood as a two-time GRAMMY winner, having earned Best New Artist and Best Female Country Vocal Performance ("Jesus, Take the Wheel") honors that year.

"I loved to sing before, but you can't get anyone to pay attention to you," Underwood told ET backstage at the awards show. "American Idol is my way in for people to start taking me seriously."

Kelly Clarkson also broke through at the GRAMMYs after winning A.I.'s first season in 2002. She went on to win Best Female Pop Vocal Performance ("Since U Been Gone") and Best Pop Vocal Album (Breakaway) in 2006.

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After winning the singing competition, Clarkson promised us that not too much would change.

"It's so exciting to win and stuff, but I'm still Kelly," she told ET in 2002. "I'm still going to call my friends."

As Idol begins to wrap up its final season, the mood is bittersweet for those who launched their careers on the show. Thursday night's finale will welcome back Underwood, who will take the stage where it all began for her one last time.

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"It's definitely bittersweet," Underwood admitted to ET at the American County Music Awards. "It's going to be a great celebration. I'm glad they've continued to let me come back."

Tune in to American Idol Wednesday at 8 p.m. on Fox to see how current finalists Dalton, La'Porsha and Trent fare.