James Joule could have observed what he did and then done nothing with it. Instead, he became driven to understand and explain it and so discovered the mechanical equivalent of heat, a forerunner of the concept of energy and the 1st law of Thermodynamics. His story is a good one, an inspiring one, an example of how good science is conducted and how a good scientist behaves. I share a piece of his story here in this video.
I go into much more detail about the life of James Joule, including his wonderful collaboration with William Thomson, later Lord Kelvin, in my book Block by Block – The Historical and Theoretical Foundations of Thermodynamics.