He said in writing doggerel yourself you immerse
And I must say that you write such trashy verse
And you waste such effort and such precious time
In writing reams and reams of slipshod rhyme.

For your efforts you don't have much to show
For on Nature's verses there's not much I don't know
Since on natural sciences I have a degree
And I know the latin names of every bird and beast and tree.

You've written on 'strepera graculina' the pied currawong
And about the beauty of 'gymnorhina tibicen' the Australian magpie's song
And such things I've known since I was five or so
But tell us something that we do not know

His self proclaimed knowledge I won't long recall
For he seemed to me a regular know it all
And to argue with him would not waste my time
I'd much prefer to write a slipshod rhyme.

The more we know the less we know we know I learnt as a boy
But 'twould seem to him this saying did not apply
And between reality and arrogance he has to discern
For like us all he too has lots to learn.

Francis Duggan

http://www.poemhunter.com/poem/a-regular-know-it-all/