Hey James - that one is slightly different and goes like this: "Do you know why John became an actuary? Because accounting was too exciting for him."
Similar to the old Royal Air Force recruitment poster, showing a young boy, on his way to school, holding his arms up as if they were wings as he's walking, pretending to be an airplane. The sub-text: "Have you ever seen a boy playing chartered accountant?"
Back on topic now I guess!