The poem
I'm just a mediocre man Of no high-brow pretence; A comfortable life I plan With care and commonsense. I do the things most people do, I echo what they say; And through my morning paper view The problems of the day.
No doubt you think I'm colourless, Profoundly commonplace; And yet I fancy, more or less, I represent the race. My name may stand for everyone, At least for nine in ten, For all in all the world is run By mediocre men.
Of course you'll maybe not agree That you are average, And unlike ordinary me You strut your little stage, Well, you may even own a Bank, And mighty mergers plan, But Brother, doff your tile and thank The Mediocre Man.

The poem is about an average Joe, or at least that's how the man sees himself. He sees himself as no different than anyone else, or most people. Most people don't see anything special about him because he is like almost everyone else. He even has a common name. The world is run by people just like him. To some people who think that they are more than average and even look down their nose at him, they have him and others just like him to thank for making the world go round.