This lecture by the instructor covers the journey from optimal transport theory to its applications in various fields such as meteorology, image processing, and machine learning. It delves into the history of optimal transport, including the works of Gaspard Monge and Leonid Kantorovich. The lecture also explores the isoperimetric problem, soap bubbles, and the connection to crystal structures. Furthermore, it discusses modern mathematical developments in optimal transport, including the Knothe-Gromov's proof and the Wasserstein GAN. The presentation concludes by highlighting the ubiquity of optimal transport in different disciplines and its significance in solving complex mathematical problems.