Be careful with what you know. After my first lesson I walked into the clubhouse with my instructor,with other instructors present, and asked if there was any reason why she didn't put the carb heat to cold before landing. This didn't go down too well when she had to admit that she'd forgotten and even I realised I'd made a slight error.
She got back at me the next flight by asking me to do the takeoff but not telling me that I needed to use the rudder to steer by. I had to apologise about the language I used when I was convinced I was going to die as we headed across the runway!
If she's reading this I'm sure she'll recognise the situation, but she did go on to teach me to fly.