This song ends with the line "Remember the fifth of November." The lyric refers to Bonfire Night or Guy Fawkes night, a British celebration whose origins go back to the early 17th century. On November 5th 1605 Guy Fawkes was discovered hiding in a cellar beneath the Houses of Parliament in close proximity to 20 or more barrels of gunpowder, a length of slow match and a lantern. He was taken to the Tower of London where he was agonizingly tortured on the rack until he named his co-conspirators. Since then the British have celebrated this escape from the Houses of Parliament being blown up. On November 5th every year, they light up bonfires, place effigies of Guy Fawkes on the fire and combine this with a firework display. "Remember, remember the fifth of November" is a poem that refers to the event.
Lennon told the January 1971 edition of Rolling Stone that his quotation from the poem was "just an ad lib." He explained: "It was about the third take, and I got to remembering, and it begins to sound like Frankie Laine, you know, when you sing, (sings) "Remember the Fifth of November." I just broke up, and it went on for about another seven or eight minutes. We started ad libbing and goofing about, but then I cut it there and just exploded, it was a good joke."