I guess I kinda knew? But more by knowledge of the equations? I don't think I ever really interpreted them in that way. My courses on electromagnetism were focused on the engineering part and how to get the observables for our circuits rather than the underlying physics. So, on second thought, the answer is: no I didn't know. It makes sense now that I see this video, but I'd not have been able to answer before seeing it. I hope students of physics, rather than the engineering ones, got better knowledge on this topic.