Article continues below advertisementPaul McCartney has opened up about the painful collapse of The Beatles, revealing the emotional toll of the band's split and his lingering sense the blame placed on him masked a deeper truth - that John Lennon's decision to leave the group triggered the end of the most famous band in music history. OK! can reveal McCartney, 83, reflected on the chaotic aftermath of the band's breakup while discussing Man on the Run, a new documentary exploring his life after The Beatles.