Paddy, the handyman (no - another one) went up to a house asking whether they had any jobs that needed doing. The man of the house asked whether Paddy could paint, and was assured he could.
"Well go round the front of the house, and paint the porch" Paddy was told. He was back after only 20 minutes! "You can't have finished already" the man of the house exclaimed. "I have Sir" said Paddy, "and by the way, it wasn't a porch, it was a BMW!"