Sometimes when you're feeling important
Sometime when your ego's in bloom
Sometime w hen you take for granted
That you're the best qualified in the room.

Take a bucket and fill it with water
Put your hand in it up to your wrist.
Pull it out and the hole that's remaining,
Is a measure of how you'll be missed.

You may splash all you want when you enter;
You can stir up the water galore,
But stop and you'll find in a minute,
That it looks quite the same as before.

The moral of this quaint example.
Is to do just the best that you can.
Be proud of yourself but remember-
There's no indispensable man.