Sincere praise at the right time can transform a person's life. We all need feedback from others. Young children have no way of knowing how well they are doing unless they get feedback from others. And we all were once children. And we never outgrow our need for feedback.
An accomplished Talmudic scholar shared with me, "When I was a young boy, I had a tendency to daydream and I didn't always pay attention when my teachers were talking. My self-image was that I wasn't especially bright. But one sensitive teacher changed my life. I had received a 50 on a Talmud test. The teacher called me over and privately told me, 'You only answered half the questions on the test. But I want to point out to you that what you did answer shows that you have a deep understanding of the concepts.' I felt good, but it didn't make too much of a difference. The next week, I once again answered only half the questions and received only a 50. Once again the teacher called me over and told me, "You didn't answer half the questions. But I want to point out to you that what you answered, you answered exceedingly well. You really understand the ideas you understand.' This opened my eyes. I saw that I had a much better mind than I had previously thought. I began to concentrate in class. The next four weeks in a row I received a 100 on each test. And after that I always got at least a 90. Sincere praise made me what I am today."
(From "Enthusiasm: formulas, stories, and insights" (2002) pp.75-7; available from http://www.artscroll.com)