People run in their dreams to escape being chased. Analysts say it's themselves chasing themselves, this explains why they can't escape. Perhaps 'The Marathon Man' is a comment about the relentless, repetitive nature of modern achievement—running a race that has no clear end, a race managed by "paper cutout" figures whose job it is to keep him consistently distracted and going up the wrong path so he doesn't have time to see exactly what they, and their friends are up to.