Ono recalls the ex-Beatle fretting about reaching that number: "I can't believe I'm going to be 40!" she said he told her.
"I said, 'John, John — 40's not so bad, you know?'"
Sadly, it would be his last year. Lennon was shot to death on Dec. 8, 1980, almost two months after turning 40.
But in the three decades since, Ono has worked to keep his legacy vibrant, and continues to do so with the approach of his 70th birthday on Saturday.
Eight of Lennon's albums have been remastered and are being rereleased this week as single albums as well as two boxed sets. There is also a remixed version of Ono and Lennon's 1980 "Double Fantasy" album.
Other projects include a "Box of Vision" commemorative set featuring artwork and a place to store Lennon's music; all-star concerts; a film about a young Lennon, "Nowhere Boy," out this week; and a screening of the documentary "LennonNYC" in Central Park on his birthday.
Ono will spend what would have been Lennon's birthday in Iceland, celebrating with a concert by her Plastic Ono Band and the lighting of the Imagine Peace Tower in his honor. In a recent interview, the 77-year-old artist and peace activist talked about her mission to keep Lennon's memory alive.
AP: John Lennon was a musician and an activist. Are enough musicians and artists trying to have an impact on social change?
Ono: Of course, they're all doing it. It's great. When John and I started doing it, you know, we were looking around — "Are we the only people?" It was a bit like that. But now I think there's so many musicians, they're very strong, strong sort of activists. All of them. It's great.
AP: What do you think would have been John's take on the turmoil in the world today?
Ono: He would have been totally angry. ... He would have felt like he wanted to run somewhere and just bang something or strangle someone, you know? But then I think, I'm sure he would have relaxed and decided he should still be an activist. We need to really do something about the world. Otherwise, we're all going to blow up together.
AP: What do you think of "Nowhere Boy"?
Ono: Well, first of all I was surprised because this director (Sam Taylor-Wood), she's beautiful, I mean physically very beautiful, (a) young person. ... But then the thing is, she made it and she was really good to make this. This is her first film. Incredible, right? She's like a miracle. And everybody performing in it, they're very good. And I was surprised, because this is the first time that anybody — well, maybe they read the books or something — but anybody understands how John's childhood was. And how much painful, how painful it was for him. ... I was very, very thankful that Sam Taylor-Wood made this film. Very truthful film, yeah.
AP: One hundred years from now, what do you want people to know about John Lennon?
Ono: First of all, I'm not sure if I'm not going to be there. Things are changing in this world so much and it might be like we're all going to live as long as we want to. And also John might come back. We don't know anything. So I'm not going to answer that question.
AP: How did you decide what music you wanted to rerelease with the boxed sets?
Ono: The only thing that I probably had something to do with, to decide, is I didn't put "Two Virgins," I didn't put "Life With the Lions," because they're too sort of avant-garde in a way. ... I wanted to introduce John as an incredible, special rocker first. And then he dabbled in some avant-garde things and that's OK, but that's a lot of me is in there, so I thought, "Well, you know, let's not do that."
AP: The song "Woman" — what does it mean for you to listen to that song years later?
Ono: Of course, it was very flattering that John wrote that. But at the same time I was the one who was around. I was very lucky. Many painters, you know, they paint their wives, which is kind of like a maybe cheap and simple way of doing it, I don't know. But that's what they do. So he used me in that sense and probably I inspired him or something. But I think he's talking about all women and I think that's very important.
AP: Do you still put his music on and listen to it?
Ono: I listened to his music almost every day or every other day or something the past 30 years because there's other requests and things, and for business reasons I listened to them. But it's not a very relaxing thing to do. I don't listen to his songs to just relax, because then, you know, it just makes me feel sort of, well — it's painful in a way.