A young man and an old man are playing golf. On the course, they come across a 40 meters tall tree.
The young man hit the ball very high, but the ball failed to cross the tree. Watching this, the old man commented 'When I was your age, I was able to easily hit over that tree'.
The thought of an old man easily clearing the tree spurred on the young man further. He again hit the ball with all his might, the ball went up and up and hit the tree one meter below the top and fell back.
'Of course', continued the old man, 'when I was your age, the tree was only a meter tall'.