The article aims to pay respects to the excellent scientist and good friend Yuri Pavlovich Yampolskii. This article describes several scientific areas that Yampolskii was actively engaged in, and is divided accordingly into three chapters. The first chapter contains information about the main group of polymers (polyvinyl-trimethyl silane, polynorbornenes, PIM-family polymers, perfluorinated polymers, etc) that Yampolskii investigated in the framework of membrane gas separation. The second chapter considers the application of the inverse gas chromatography technique for the characterization of penetrant sorption in polymeric membrane materials (highly permeable glassy polymers) that was mainly developed by Yampolskii's group. The third chapter describes the work of Yampolskii's group on computational chemistry, compiling gas transport data into the TIPS RAS Database, its capabilities in correlation analysis, and "structure-property" predictions. We will miss our beloved teacher and colleague and hope this article will, to some extent, tell a story of his eventful and energetic life in the scientific world.