“I said something wrong/ Now I long for yesterday…” Paul McCartney sang these poignant lyrics nearly 60 years ago in his somber song 'Yesterday'. Recently, he revealed in his podcast the actual meaning behind them.

During his A Life in Lyrics podcast, McCartney states that this lyric was inspired by a moment in his childhood in which he mocks his mother. He explains that his mother was a nurse with Irish roots, so she "talked posh" in comparison to the rest of his family.

“I know that she said something like ‘Paul, will you ask him if he’s going … ’

“I went ‘Arsk! Arsk! It’s ask, mum.’ And she got a little bit embarrassed. I remember later thinking, ‘God, I wish I’d never said that’. And it stuck with me. After she died I thought ‘Oh f***, I really wish… ’”

At first, McCartney, 24 years old when the song was written, said he'd dismissed the suggestion that Mary McCartney’s death from cancer 10 years prior had been the inspiration for the song.

“It may be that there is so much tumbled into your youth and your formative years that you can’t appreciate it all. Sometimes it’s only in retrospect that you can appreciate it.”

’When she died, I wonder, ‘I said something wrong,’ Are we harking back to that crazy little thing? I don’t know. Does this happen? Do you find yourself unconsciously putting songs into girl lyrics that are really your dead mother? I suspect it might be true. It sort of fits if you look at the lyrics.”

Nevertheless, BBC Radio voted 'Yesterday' Best Song of the 20th Century in a 1999 2 poll. The song was also inducted into the Grammy Hall of Fame in 1997.

Listen to 'Yesterday' from their 1965 album Help!