When Jesus said "I Am." he was letting us fill in the blanks. He am everything.
In a lesser way, the same is true of our sun. Every emission of energy in our world is a re-use of the power coming from the sun. A thousand cars jostling each other in a traffic jam are all powered by energy from the sun captured a million years ago by decaying matter on it way to becoming coal or gas. (If they honk their horns it is the same.)
In Chapter One of John's Gospel we say, "In him was life, and the life is the light of the world." When someone in the old comic strips had an idea, the cartoonist would illustrate that by having a. light bulb turn on over the msn's head. In a similar way, when St. John wrote. "In him was life, and the life was the light of the world" he was saying that every thought any of us has is a re-use of the mental energy of him who is all the thinking there is..