Sir Paul McCartney revealed that his bandmate was once over excited after performing three shows in one night in Hamburg, Germany - without realising the band was slated to perform a fourth one.
An almost naked Lennon gave a drunken performance but McCartney insisted that the Fab Four were still disciplined compared to their contemporaries.
"(There was) plenty of wildness back then, (but we were a) fairly sober lot compared to some of the guys. We were so knackered, working the amount that we did, that we mainly slept," The Daily Express quoted McCartney as telling Shortlist magazine.
"Occasionally, you'd think you had three shows in the evening and after the third you might party down a bit. Then you were told you'd got four. So I do remember John coming on once in his underpants with a toilet seat around his neck," he added.