"Physical fitness is not only one of the most important keys to a healthy body, it is the basis of dynamic and creative intellectual activity. Intelligence and skill can only function at the peak of their capacity when the body is healthy and strong." - President John F. Kennedy

Personally I believe that he is right on the whole the body has to be healthy and strong in order for the intelligence and skill to function. For example, the health and the fitness state of a flower is the water, nutrients, and sun that it needs to grow. And the blossoms of and sprouts its petals to show its true state is the intelligence and the skills. So you see in this example if the flower doesn't have the healthy and strong state then what are the chances its growing to grow. Another example, is the book itself, the story is amazing but you needed the inspiration and the creativity to write the story. If you didn't have that then your writing skills wouldn't make sense and do poorly and so will your story. So you see no matter what you do you need the healthy body and the strength to use your full advantage of intelligence and skill. and those intelligence and skills is your performance and your dynamic input and idea on the topic. The tree itself is there for you it helps you more than you help it. it gives you shade, food, resources, and helps you breath. But yet, you treat it like nothing and use it all up until its gone. and at the end it wasn't even worth it. don't let the tree die and don't use it up. Think about what you  are doing and give back to the tree. so that you can learn and grow. use the your brain and your strength to so what is right.