When you go to the fishing pond as Adult Link the pond owner wearing a hat. He mentions about his hair but doesn't say what is wrong with it. Well go to his right and keep aiming at his hat with your lure and casting and soon you'll get his hat!!! You'll find out what is wrong. Give him his hat back and you'll be complimented on your generousity. Cast it in the water and pay Fifty Rupees to him.