This song was George Harrison's tribute to John Lennon, shortly after Lennon was murdered by Mark David Chapman.
Though George had idolized John in his younger days, they two had been feuding bitterly for quite a few years before John's death. This song was George's way of telling John, "In spite of everything, I always loved you, I was always inspired by you, and I always admired the messages of peace and love and idealism you tried to share with the world."