Bob was an avid golfer and, even at seventy-two, could still hit a fine drive. But finally, he went in to his doctor to complain that his eyesight was getting so bad that he often couldn't see the ball.
'Well, Bob,' said the doctor, 'you know, when you get older something's got to go, and there's not much I can do about it. Now, I do have this patient named Joe - he's getting on in years and not as sharp as he used to be and he's deaf as a post, but he's got twenty-twenty eyesight. Why don't you take him with you the next time you go golfing?'
The arrangement seemed a little curious to Bob, but worth a try, and so the next Saturday he found himself out on the fairway with Joe and hit a beautiful drive.
'Well, Joe' he said turning to the old guy, 'did you see it?'
'Oh, yes,' said Joe, 'clear as day. If only I could remember where it landed!'