My first instructor was a bit of an ass. She'd be nice one second, and the next she was picking out every tiny thing that I did wrong, telling me to pull over and half yelling, half lecturing me on the fact that I indicated a few seconds too early. She also seemed to like ripping me off. As in, she would be constantly be late and drop me off like ten minutes early. And yet, the one time where I was about five minutes late (I had an appointment just before my lesson) the first thing she said to me was "so can you tell me next time you're planning on being late because you've just wasted five minutes" in the snappiest voice I've ever heard.
The lesson after that, I switched instructors.
She also kept me on quiet roads for over 2 1/2 months and didn't teach me manoeuvres until like 3 months in.