Calibration

How do you know if you're doing something too much or too little?  How to tell if you've judged it just right, or are doing it differently from everybody else?

Partly by practice.  The strangers around you on the road will make their opinions known!  But, better, take the advice of people who already drive a lot.  Better still, ask someone whose job it is to recognise a good standard.

Ultimately, taking a formal test will tell you if you've calibrated your decision-making correctly.  Still, it's less disappointing if someone's told you that you are performing at the expected standard.  That's why mock tests are important before the real thing.