Nobody's perfect, as the saying goes, and Paul McCartney will attest to that. His performance of 'Hey Jude' at the 2012 Summer Olympics began awkwardly, which, to those of us watching at home, was strange given how many times he's sung that classic throughout the years. In a new interview, he explained what happened that caused the mix-up.

"I f----- up," McCartney told the NME, "I was supposed to wait for a cue. But I forgot." So what made the legend lose his place? "Well, there's this bloody great bell that we didn't know about." he explained. "It was deafening. We were live, everyone was there, the world was ready and this bloody great bell goes off."

Due to the scope of the event, the band had prerecorded a playback to use just "in case all hell broke loose."  McCartney continued. "I forget I've gotta wait for it, so I go, 'Hey Jude', and someone presses the playback. So there's me on the backing track, and actual me, two of us singing."

However, that didn't let the mishap sour the evening. "The drummer wouldn't look at me because he was in hysterics and I was thinking, 'What have I done?' There was no stopping, it was the Olympics."

Watch Paul McCartney Perform 'Hey Jude' from the 2012 Olympics