It’s the first day of Boot Camp on The X Factor, but host Olly Murs is having scary flashbacks to his own time as a contestant on the show.

The singer, who was a runner up in the sixth series back in 2009, revealed that Boot Camp brought back painful memories, calling it a “tough time”.

In one Tweet, he recalled losing sleep over the competition, being very nervous, and even forgetting his lyrics.

After stunning the judges with his audition six years ago, Olly performed Elton John’s Your Song at Boot Camp, which left judges disappointed. Simon Cowell commented: “You know what’s frustrating, he was one of those guys who could have taken a risk, and instead he took the safe option.”

Luckily, the 31-year-old redeemed himself at the live shows, where Simon declared that his performances were “in a different league”. He has gone on to success with songs such as Dance With Me Tonight.

2015 is the singer’s first year hosting The X Factor with co-host Caroline Flack.

Auditions only finished on Thursday, but filming for Boot Camp is already well underway. Judge Nick Grimshaw shared a photo of himself doing a piece-to-camera for the show.