The discussion focuses on a summary of Hamilton-Jacobi mechanics, drawing inspiration from Goldstein's work on Lagrangian and Hamiltonian formulations of classical mechanics. The author presents the content in an informal style, aiming to make it accessible and useful for readers. There is a suggestion to enhance the summary by including a derivation of the Euler-Lagrange equations based on the principle of least action. This addition could provide a more comprehensive understanding of the topic. The overall goal is to clarify and enrich the discussion around Hamilton-Jacobi mechanics.