Britney Spears celebrates 20th anniversary of 'Oops!... I Did It Again' album

Pop star Britney Spears is celebrating 20 years of her second album 'Oops!... I Did It Again' and she says it's unbelievable how time flies.

The 38-year-old singer, who is said to have influenced the revival of teen pop during the late 1990s and early 2000s, shared a fan-made compilation of her interviews and behind-the-scenes from the recording studio at the time of the album's making on Instagram.

"Thank you to whoever made this. 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 wrote on Saturday.

"Thank you for sticking with me and growing with me. I am one Lucky girl," she said in a reference to her track "Lucky" from the same album.

"God bless and thank you all! PS you see even 20 years ago I still liked to twirl," she added.

'Oops!... I Did It Again' released on May 16, 2000 and it held the record for 15 years for the biggest sales week ever for an album by a female artiste, debuting at No 1 on the June 3, 2000-dated Billboard 200 with 1,319,000 copies sold in its first week.