 Srinivasa Ramanujan was a largely self-taught genius who emerged from an orthodox Hindu family to become one of the most influential mathematicians of the 20th century. Although he had almost no formal mathematical training, his remarkable intuition led him to make extraordinary contributions to several areas of mathematics, including, in particular, number theory. Now, almost 100 years later, we look at his life, his work, the legacy he left behind, and also meet some of the mathematicians influenced by his work. What he studied 100 years back is what we are doing today. Well, I was really fascinated by the story of Ramanujan when I was young. I think very influential in, I think, number theory. In genius. That's who I'm asking. In mathematics, we have somebody who's a God figure, and that is Ramanujan. Little Ramanujan grew up in the temple town of Kumbakonam, located on the banks of river Kaviri. In the thinnest schools, the unique function of the pedagogy is to cultivate a memory which scholars would call it recollective memory, which is you remember and you memorize in order to be able to recollect. The book that really transformed Ramanujan's life is Gar's synopsis of elementary results in pure mathematics borrowed from the local college library. He engrossed himself in its methods of analysis and demonstrations, and proved the propositions and formulae contained therein all by himself. In 1904, at the age of 16, based on his outstanding performance in school, Ramanujan won a scholarship to the government college in Kumbakonam. By this time, he had already started producing original research. From the age of 14, Ramanujan wrote down his mathematical findings in three notebooks, which have become famous now as Ramanujan's Frayed Notebooks. An intense Ramanujan, constantly toiling with equations, struck a rich purple patch with hypergeometric series, elliptic functions, q-series, continued fractions, consuming all his youthful energies. This productive period was briefly interrupted in 1909, when as per the prevailing customs, Ramanujan's parents arranged his marriage to Janaki. For some time, he tutored students in arithmetic and somehow eaked out a frugal livelihood. Finally, he got a clerical job, largely due to the chairman, Sir Francis Spring, of the Madras Port Trust, getting thoroughly convinced of Ramanujan's mathematical ingenuity. You know, people like Professor Ramasamy. Actually, he was a government servant. He was one of the founders of Indian mathematical society. People like him encouraged Ramanujan to write. I mean, till then, Ramanujan was sort of keeping a journal. You know, his notebooks. I mean, he was just keeping it to himself, maybe showing to a few people. They said, no, that's not the way, for example, science is done in, you know, modern world. So they encouraged him to publish. So some of his earlier papers came in India Journal for Mathematical Society. You know, I mean, his work on probabilistic number theory or elliptical function or continued fractions. They all have a lot of application even today. It is here at the Trinity College that Professors G. H. Hardy, and to a lesser extent, J. E. Littlewood, mentored Ramanujan only to be continually amazed by his remarkable originality. Later generations of mathematicians were to proclaim his conjectures as unexpected, elegant and deep. Our Indian research student wrote over 30 papers, seven of them jointly with Professor Hardy. And ultimately, he was delighted to be finally bestowed with the University of Cambridge degree. These papers shaped the course of 20th century mathematics in the most unimaginable way during his lifetime. Ramanujan was a pure mathematician who was interested in numbers for their own intrinsic beauty. But, surprising as it may be, his work still has an impact on our daily lives. Ramanujan's work tells us something about how to build transportation networks. A second application of Ramanujan's work is important for modern web applications, such as Facebook. In particular, Ramanujan-type graphs arise in the design of algorithms for detecting communities or groups of people with shared interests in such social networks. Now, both music and mathematics are about patterns and about stringing together patterns in a way to tell a complete story. As someone has said, mathematics is like a big symphony in which various, you hear various themes, they come together, they interview with each other, they sometimes dissonance a setup. Various things happen, but Ramanujan, for example, the themes Ramanujan set up through his work, they continue to be heard in mathematics. Subsequently, the study of black holes connects back to the work of Ramanujan. So, in many ways, all the great truths in science and mathematics ultimately come together and are connected. This, then, is the legacy of a self-trained mathematician who straddled the world of numbers in early 20th century and continues to inspire generations of mathematicians even today.