Indeed. I was 9 weeks into my sophomore year in high school. My sinuses were not doing well with the band field shows. I arranged to swap band for chemistry. Everyone in that classroom was a junior or senior. My dad recommended cracking the textbook for the class and doing all the chapters and questions to catch up. It was 3 1/2 weeks later that I finished the whole book. Easy A. The next year I was a senior (having accrued enough credits to rate the class standing). The pattern continued until I graduated from UCSD at age 19. Give me the book and in due course it will be mastered.