I'm a junior developer, how should I comment my code?

Hi, I don't know a good answer to this question. When I'm creating a Pull Request, my team leader always makes my code look like a history book: he wants every function to be commented, every field to be commented, every action in every step of every function to be commented.<br><br>I've studied programming for six and a half years, and I've never seen anyone comment their code so much. What are the most important things to comment in our code?