The 'Womanizer' singer admits watching the special storyline, which aired in the US last night (28.09.10), took her on a trip down memory lane.
Referring to her debut single '…Baby One More Time', performed by Lea Michele, Britney – who guests stars in the episode – wrote on her twitter page: "Watching Baby brings back so many memories! Feels like yesterday. (sic)"
The 28-year-old pop star also joked she was terrified of actress Jane Lynch, who plays intimidating cheerleading coach Sue Sylvester.
Speaking about Jane, she joked: "Jane Lynch scares me."
Britney then added: "Jane Lynch is hilarious and scary all rolled into one."
The singer also praised Heather Morris – who plays ditzy cheerleader Brittany Pierce – for being able to dance with a snake like she did in to her song 'I'm a Slave 4 U' at the 2001 MTV Video Music Awards.
She wrote: "Awww Heather Morris is sooo cute! Brittany S Pearce. Ha! She was so fun to work with and was really sweet in person.
"I know how hard it is to dance with that snake! Nice job. (sic)"
On conclusion of the episode, she gushed: "I loved it! Thank you guys SO much for making this happen! (sic)"
A number of guest stars are due to appear in the second series of 'Glee', including Gwyneth Paltrow, Javier Bardem and Carol Burnett.