Sir Isaac Newton discovered gravity around 1665 while he was drinking tea and observed an apple falling from a tree. Newton deduced that the force that caused the apple to fall to the ground also is the same force that causes the moon to orbit the earth.
When he was growing up, Newton spent much of his time on his family farm reading. Newton was an average student at best. In 1665, when his school shut down due to the plague, he came up with his own ideas and theories on motion, gravitation, calculus and even the components of white light.