Why Imagine is the perfect hymn for the post-modern world

Imagine, by John Lennon, has become the sacred hymn for the post-modern Baby Boomer Left.  But beyond the silly lyrics which don't really stand up to any real scrutiny, I've noticed something.  For a fellow who asked us to join him in imagining no possessions, he seemed to be pretty keen on keeping the possessions he had.  I've often felt this is why Imagine is the perfect theme song for modern progressive thought.