Joke

A man asked his doctor if he thought he'd live to be a hundred. The doctor asked the man, "Do you smoke or drink?"


"No," he replied. "I've never done either."

"Do you gamble, drive fast cars, or fool around with women?" Inquired the doctor.

"No, I've never done any of those things either."

"Well, then, " said the doctor, "what do you want to live to be a hundred for ?"


My question:

Who can explain which point is funny because it's a joke? I haven't got the funny point so far indeed? Thanks in advance. If you see this post and you know which piont is funny, please tell me the details.