Mr. Oppotknockity is a supurb piano tuner. He has spent more than 30 years honing his craft and has made quite a reputation for himself.
He got a call from a guy who had just bought a new grand piano and requested Mr. Opporknockity to come and tune it. Mr. Opporknockity spent more than 3 hours tuning the grand piano to perfection, collected his fee and left.
A couple of days later, the customer calls Mr. Opporknockity and informs him that the piano is not in tune. The customer demads Mr. Opporknockity to return and re-tune the piano. To which Mr. Opporknockity replied, Opporknockity only tunes once.
