How I learned to mind my own business

I was walking past the mental hospital the other day,
And all the patients were shouting, '13....13....13.'

The fence was too high to see over, but I saw a
Little gap in the planks, so I looked through to see
What was going on.....

Some idiot poked me in the eye with a stick!

Then they all started shouting '14....14....14'...