If you’re having trouble finding the Cinemachine Impulse listener like I was - I spent a good 10 minutes trying to figure out how to add the component - make sure that you rewind to 30 seconds into the lecture and watch closely. The instructor isn’t clicking “Add Component”, he does “Add Extension” under CinemachineVirtualCamera. Adding CinemachineIndependentImpulseListener isn’t the same thing! Hopefully this helps someone 
