John Lennon's son Julian has reconnected with his childhood friend and the inspiration for the Beatles' song "Lucy in the Sky with Diamonds."

The real 'Lucy in the Sky with Diamonds' is gravely ill

They are linked together by something that happened more than 40 years ago when Julian brought home a drawing from school and told his father, "That's Lucy in the sky with diamonds."

Just the sort of cute phrase lots of 3- or 4-year-olds produce — but not many have a father like John Lennon, who used it as a springboard for a legendary song that became a centerpiece on the landmark album "Sgt. Pepper's Lonely Hearts Club Band."