I assumed he was referencing 'Time' from Dark Side of the Moon: "And then one day you find ten years have got behind you. No one told you when to run, you missed the starting gun"

Kinda related and a bit more pithy is John Lennon's one from Beautiful Boy: "Life is what happens to you while you're busy making other plans."

more from Lennon:

  Imagine there's no Heaven
  It's easy if you try
  No hell below us
  Above us only sky
  Imagine all the people
  Living for today

  Imagine there's no countries
  It isn't hard to do
  Nothing to kill or die for
  And no religion too
  Imagine all the people
  Living life in peace

  You may say that I'm a dreamer
  But I'm not the only one
  I hope someday you'll join us
  And the world will be as one

  Imagine no possessions
  I wonder if you can
  No need for greed or hunger
  A brotherhood of man
  Imagine all the people
  Sharing all the world

  You may say that I'm a dreamer
  But I'm not the only one
  I hope someday you'll join us
  And the world will live as one

0 points for the greatest song of all time? and it's about dreams! a particular dream.

For some reason the previous lines resonate with me better. Tired of lying in the sunshine staying home to watch the rain. You are young and life is long and there is time to kill today.

Yes, that's the line.