The Happy hitmaker reveals his time as a server at the popular burger joint was short-lived because he would always get distracted by the music, so he couldn't believe it when he was offered the chance to work with MCDonald's bosses again once he found fame.

Williams crafted the I'm Lovin' It hit for Justin Timberlake and the track went on to be used on the firm's advertisements worldwide.

However, the star insists he didn't consider the work "revenge" for being fired as a youngster, explaining, "I just couldn't believe that I got that opportunity... That was just like a crazy thing because I got fired from MCDonald's three times, not just once. Three different locations...

"I was lazy. I was very lazy. (His manager would say), 'Williams, go mop the (floor).' And I'd go out there, but the problem is I'd get caught up in the music out... in the dining area, so the music would be playing and I'm like (dancing and singing to the songs). At a certain point they realised that I was no help. I was only good at eating the chicken nuggets."