Assume you are not keeping up with everything that is covered in the fast.ai course. Should you worry?
Answer
Do not worry - Jeremy is trying to give us enough material in the lectures to keep us busy till next year's offering of the course.
Relevant part of lecture
supplementary material
...you can dive into the bits you're interested in, and go back and look over stuff - don't feel like you need to understand everything within a week of first hearing it - Jeremy