On a demolition site on adjoining toilets that had been outhouses in someone's back yard

It's no good standing on the seat
the crabs in here can jump six feet
and if you think that's rather high
try next door, the b*st*rds fly.

And next door read:

In this place of rest
we do our best
to keep it clean and sweet
so God bless your soul
and sh*t down the hole
and not upon the seat.

My Dad's favourite was on a particulary heavily written upon wall.

One would think with all this wit
That Shakespear's ghost came here to s*it.

And as George P said, isn't it weird what one's memory retains?