Explore the fascinating world of Ramanujan's tau-function in this captivating lecture by Eknath Ghate. Delve into the sequence of numbers 1, -24, 252, -1472, 4830, and beyond, which have been a driving force in Number Theory for nearly a century. Discover how these intriguing numbers continue to challenge mathematicians with easily understood yet unsolved problems. Journey through various mathematical concepts, including Math Circles, Euler's work, patterns, Wyler's Theorem, partitions, and the famous Gauss story. Learn about modular forms, Galois theory, group theory, and their connections to Ramanujan's tau-function. Gain insights into the significance of the Fields Medal and explore the aesthetic appeal of mathematics. This comprehensive talk, presented at the J. N. Planetarium in Bangalore, offers a relaxed introduction to Ramanujan's tau-function and showcases some of the speaker's own findings on this captivating mathematical subject.