To be honest, not very much. I found some topics difficult and some did not make sense. I loved some aspects of physics like waves, force and energy, explanations for why the sky is blue and the grass green. Some topics like electricity, magnetism, resistance, hydraulics i found very challenging. So I tried to work extra hard on these topics and even went for tuition from my classmates who were very good in Physics (it was a struggle). I was more of a biology and chemistry type of person in school. I found going for group discussions after class to be very helpful.