Marcello Costa is a Neuroscientist retired in 2022 as Matthew Flinders Distinguished Emeritus Professor after 47 years of teaching and research at the School of Medicine of Flinders University in South Australia. He published his first paper in Neuro-gastroenterology in 1965 while still a medical student at the University of Turin, Italy. He pioneered many methods to investigate the organization and functions of the so-called 'little brain in the gut', the Enteric Nervous System. This monograph summarizes his extensive work in collaboration with close to 200 colleagues from different countries. He participated in and organized over 100 scientific meetings. In parallel to his numerous travels for scientific meetings he recounts some of his adventures in the wilderness and his plan to develop a novel broad perspective of the relation between the brain in the external world.