His ballad ‘Yesterday’ is one of the most covered songs in history-but as he turned 70 on Monday, ex-Beatle Paul McCartney shows no signs of settling back to reflect on his extraordinary past. Fresh from wowing huge crowds at Queen Elizabeth II’s diamond jubilee concert and with another headline gig-the London Olympics opening ceremony- booked for next month, retirement looks a way off for the British legend. “If I’m really enjoying this, why retire?” the most prolific, most commercially-successful former member of the Beatles told the British music magazine Mojo. “People say to me, ‘You work so hard’,” added McCartney. “We don’t work hard, we play music.” Between his years with the Fab Four, his work with Wings and his solo career, McCartney has written or co-written more than 50 top 10 singles. Macca, as he is affectionately known, released his latest album ‘Kisses on the Bottom’ in February, and is just finishing a world tour. Born to working-class parents in the port city in northwest England, McCartney met John Lennon at the age of 15 and the pair formed the Quarrymen, the skiffle band that eventually metamorphosed into the Beatles. McCartney, Lennon, George Harrison and Ringo Starr would become synonymous with mobs of screaming fans, mop-top haircuts, and an image of four men strolling over London’s Abbey Road at a zebra crossing. Lennon and McCartney formed one of the most celebrated songwriting partnerships of the 20th century, but their creative differences ultimately helped bring about the Beatles’ break-up in 1970. He has a son and four daughters-including high-profile fashion designer Stella and Beatrice, born to Mills in 2003. Of the four Beatles, two have since died: Lennon when he was shot dead in New York in 1980 and Harrison from cancer in 2001.