One of the lessons I took onboard during my training is that calm is just as infectious as panic. I flew with both nervous and bomb proof instructors, and I figured out later on who I'd much rather fly with. I flew with a nervous instructor just after my first solo so knowing for certainty I was capable of flying the aircraft meant I felt better about my flying, but I note from my logbook I didn't get much solo time after flying dual with them.
The story about a bomb proof instructor (a former Ag pilot) was one day we were doing circuit training at a small country airstrip, I'd landed long and had my eyes inside the cockpit fumbling for the flap lever. He nonchalantly looked over at me and drawled in a calm matter of fact tone, "Flyinkiwi, if you don't go around right now we are going to go through the fence." He certainly got my attention back to where it should have been all along!