Britney Spears Celebrates 'Oops!...I Did It Again' Album Turning 20

Britney Spears almost can't believe that her hit sophomore album, Oops!...I Did It Again, was released 20 years ago.

The pop star came across a compilation of clips of herself circa 2000 and was impressed enough to share it on social media.

"Thank you to whoever made this," she wrote on Instagram Saturday (May 16), the set's 20th anniversary. "I just nearly dropped my phone I wasn’t expecting it!!!!! 20 years since the Oops! album …. the anticipation and the butterflies I felt before it came out were crazy …. all of my expectations were exceeded!!!! And it’s all thanks to you folks."

Spears added: "Thank you for sticking with me and growing with me. I am one Lucky girl. God Bless and thank you all!!!!!! PS you see even 20 years ago I still liked to twirl!!!!"

The video features interview clips with Spears at the time, as well as glimpses at her in the recording studio and at the album's photo shoot.

Following its release, Oops!...I Did It Again held the record for 15 years for the biggest sales week ever for an album by a female artist, debuting at No. 1 on the June 3, 2000-dated Billboard 200 with 1,319,000 copies sold in its first week.

Take a walk down memory lane with the Oops!-era montage and Spears' original music video for the album's lead single below.