The artist still finds her late husband's 1971 peace anthem a particularly moving track and despite hearing it so often, she still sometimes sheds a tear when hearing it played.
Speaking about playing the song in Reykjavik, Iceland, by her Peace Tower in the city earlier this month to mark John's birth, she told The Times newspaper: ''I was choked up. I was thinking, 'How many times have I heard John sing this song?' But it's always very emotional.''
Yoko, 80, also tears up when she remembers how she treated John to some chocolate two days before he was shot and killed by a crazed fan in new York in 1980.
She added: ''When John passed away we had been trying not to eat chocolate, to be healthy. He loved chocolate so much.
''Two nights before he died, he was in the studio, and I thought I'd go out and buy something. I thought, 'Why don't I get him a chocolate bar?' So I came back with a chocolate bar.
''Even now it makes me choke up a bit, I didn't know he was going to die, but he was so happy that I got him chocolate. Isn't that amazing?''
Many ticket-holders couldn't get into the O2 Arena show on Tuesday night (September 19th) because they didn't bring photo ID to match their booking.
An album re-release, a new song and a documentary mark the singer's legacy this year.
The actor plays the titular hero in the forthcoming adaptation.