I read somewhere that a director's most important role is to help cast members get over their fear of failure. The director who did that for me changed my life.
I was playing Vi Moore in Footloose. I was floored when I was given a part with a solo and hopeful that if the directors saw potential in me, then it must be there. But when it came time to actually rehearse "Learning to Be Silent" with just the musical and the stage director, my throat got all tight and I slaughtered the song. When I finished, I wanted to hide. I waited to be told everything I was doing wrong and worried that I might get booted out of the role. Instead, the stage director pointed out the one line I'd sung well. She said that one line was exactly what they wanted. I just needed to get the other lines to sound like that. That one experience changed my world. I realized I could do it, I had the capacity. If I could do it with one line, I had to be able to do it with the whole song.
It was also how I needed to approach my parenting. And when I, myself, became a director, it was how I directed my cast. They astounded us all with what they were capable of, once we gave them evidence that they were capable.