I remember reading in a book about zen (cannot remember the name for the life of me) where the writer (an older man) said that he was not afraid of death, but that he understood why younger men were. He had lived his life and was happy, complete, whereas a younger man still has much of his life in front of him so it was not as bad for a younger man to be afraid of death. (paraphrased through my bad memory..)
I suppose being 'Zen' and accepting death are things that come with age. Generally speaking.
A little off topic, but relates to lines 5-8.
We should all take ourselves seriously...and then crumple that image up and toss it out the window.