This 15-minute conference talk by Chandramouli Chowdhury at the International Centre for Theoretical Sciences explores the simplicity of cosmological correlators as part of the "Positive Geometry in Scattering Amplitudes and Cosmological Correlators" program. Discover how mathematical structures in perturbative on-shell scattering amplitudes connect with cosmological correlators that capture fundamental physics of our Universe. The talk contributes to bridging two different disciplines: mathematical aspects of scattering amplitudes and cosmology. Learn about recent developments including unitarity methods, recursion relations, worldsheet models, bootstrap methods, and connections to positive geometry, positive Grassmannian, Associahedron, and the Amplituhedron—all pushing toward a reformulation of perturbative S-matrix using new principles.