The fellow wasn't feeling well, so he asked one of his co-workers to recommend a physician.
"I know a great one in the city, but he is very expensive," said his colleague. "He charges $500 for your initial visit and $100 for each visit after that.".
The man decided to see this doctor and save a little money, too. He walked in and cheerily announced,
"I'm back!".
Not fooled for a second, the doctor quickly examined him and said,
"Very good, just continue the treatment I prescribed on your last visit.."