An eight-year-old boy named Jeremy was having his annual checkup and the pediatrician began tapping on his chest. 'Do you hear that sound?' he asked. 'That is the sound of your lungs. Do you know what your lungs are filled with?' 'Air,' said the boy. 'And do you hear that solid sound?' the doctor continued. 'That is your heart. What is your heart filled with?' 'Love,' Jeremy said.