"Un Mundo Feliz" is a television series from Spain that aired in 1981. It focused on the life of Santiago Ramón y Cajal, a renowned Spanish neuroscientist and Nobel Prize winner. Cajal is celebrated for his foundational work in neuroscience, particularly for his discoveries about the structure of the nervous system. The series likely explored his life, scientific achievements, and the impact of his work on the understanding of the brain and nervous system. It aires in two paits on 29 of July and 5 of August 1981.