The WISE, The NOT-WISE, and The REST

For a life spent in teaching and schools
Dealing with both genius and fools, 
Then without malediction
I can say with conviction,
I never had quite the right tools.

For it took me a long time to find
And the difference was hard to define:
The wise oft were demented, 
The dull – vague but contented, 
And both could be quite asinine.

Whilst the average student was fine, 
‘Twas these others who took up my time. 
The norms kept me sane, 
While the rest were a pain, 
But have given me cause for this rhyme.