One day, a son asks his dad, “Daddy, would you like to run a marathon with me?” The father says, “Yes”. And they run their first marathon together.
Another time the son asks his dad again “Daddy, would you like to run a marathon with me?” The father says, “Yes son”.
One day, the son asks his father “Daddy, would you run the Iron man with me?” The Iron man is the most difficult triathlon ever (2.4 mile swimming, 112 mile biking, 26.2 mile running) And the dad says, “Yes”. The story looks simple until you watch the following clip.