> the prof expected us to use […] and I had missed that lecture You just gave me a wave of nostalgia. That’s how I survived all of my math and physics classes.

> the prof expected us to use […] and I had missed that lecture You just gave me a wave of nostalgia. That’s how I survived all of my math and physics classes. If you develop an intuitive understanding of the material, you can derive things as needed from a few core principles you do remember. A bit sad when learning is the way to subvert an educational system, though.