I recall one time when I had a manager tell me that I was not performing up to expectations. I had no idea. I thought I was doing pretty well. At the time I was pretty young and inexperienced, so not a huge surprise. He was calm but direct, did not turn it into a personal attack, and had some specific examples of things that needed to improve. I apprecated this, I worked on the things that he wanted me to improve upon, and ended up getting top perormance reviews not long afterwards.