The death of John Lennon crossed 40 years earlier this month — but it understandably still affects his loved ones and friends on a daily basis, Paul McCartney included.

McCartney, 78, is currently on the press circuit for the release of McCartney III, which arrived on Friday. In a new interview with CBS News, he spoke on the album and also talked the Beatles—just a few weeks after the 40th anniversary of Lennon's tragic murder.

Paul McCartney on John Lennon's death: It's still "very difficult"

Speaking with Seth Doane of CBS News, McCartney was asked how he's processing the loss of Lennon now 40 years on. "I'm not sure I am," he said. "It's very difficult for me, and I occasionally will have thoughts and sort of say, 'I don't know, why don't I just break down crying every day?' Because it's that bad."

Asked if he does have such breakdowns, McCartney added: "Not every day, you know? There will be times that I just have memories and just think, 'Oh my God, it was just so senseless.'"

2020: Paul McCartney talks 40th anniversary of John Lennon's death.

However, Paul shared a touching answer to what he does when a Beatles song comes on the radio. "Turn it up! Turn it up! Sing along with it," McCartney said. "It always takes me back to the session, you know, it always reminds me, 'Oh yeah, I remember John was there, Ringo was there, where we did this one. [...] It's great, it takes you right back like a flashback."

Paul McCartney remembers John Lennon in 2020

McCartney had earlier marked two emotional anniversaries for John Lennon in 2020. On Oct. 9, he paid tribute on what would've been Lennon's 80th birthday with a bittersweet memory of the pair sharing a laugh in the studio.

Then, on Dec. 8—the 40th anniversary of Lennon's death—McCartney wrote: "A sad sad day but remembering my friend John with the great joy he brought to the world. I will always be proud and happy to have known and worked with this incredible Scouser! X love Paul," with another in-studio photo seen below.

In another recent interview, McCartney spoke on being able to reconnect with Lennon after the Beatles had broken up and before his friend's death in 1980. McCartney III, the follow-up to 1980's McCartney II, dropped on Dec. 18.

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