Here I sit...

Like any boys’ school the world over, the lavatory cubicles at my secondary school were out of bounds except when supervised by a prefect, and even then the anarchic element managed to scribble rude words on the cubicle walls.

Now and again pure puerility rose to poetic heights of woe

Here I sit, broken-hearted,
Paid a penny, only f*rted.

And in contrast, smug satisfaction

Here I sit, sly and artful,
Paid a penny, did a cartful.

In those days of course, it cost a penny to use public conveniences, hence the euphemism ‘spend a penny’ to mean a quick trip to the loo, in whatever context.