I have been to a lot of track days as a driver and almost none as a passenger. When a friend offered the second seat in his caged E46 for a full Saturday, I said yes mostly out of curiosity.
The first thing you notice is how much earlier a good driver does everything. Braking happens sooner and more gently than it feels from behind the wheel, and the car is already settled before the corner arrives.
The second thing is how little drama there is. Nothing is hurried. There is no sawing at the wheel, no last-moment corrections. It looks slow and the lap timer disagrees.
By the fourth session I had stopped bracing against the door and started watching his hands. There is a lesson there that no amount of solo laps had taught me.
Most is an underrated circuit for this. It is technical enough to punish sloppiness and forgiving enough that punishment means a lost second, not a lost car.