"Certainly to me it has been valuable to have to think through the basics of physics in order to present them in a halfway coherent form for a course. That has led me to ideas in research. Even freshman physics leads to thoughts that lead to other thoughts that are stimulating."
James Peebles is a Canadian-born American physicist and cosmologist. He made foundational contributions to modern physical cosmology, including work on the cosmic microwave background and dark matter. Peebles received the Nobel Prize in Physics in 2019.