It's rude to expect others to fix things for free.
Ken's best friend Jacob is a mechanic and Ken's car has a problem with its transmission.
Ken wants to ask Jacob to fix his car.
Ken asks Jacob if he'll fix his car for him if Ken pays him his normal rate.
Ken asks Jacob to fix his car for him for free because they're best friends.
Jacob agrees to fix Ken's car and gets it up and running within a day.
Jacob refuses to fix the car for free and then stops talking to Ken because he thinks he'll be asked for more favors.