Speaking of encouragement, I'm glad that this guy Ross doesn't attend my Muay Thai classes anymore. I was frequently partnered with him, since we were at the same rank. He was a very dour fella. He routinely provided criticism, but he never provided positive feedback -- not even once. That got really old.
He was more skilled and more experienced than I, since he had prior martial arts training. He failed to understand that positive reinforcement is helpful and even necessary.
Some of the more advanced practitioners in our class understood that, which made them great to work with. Too bad he didn't. This made him a real pain.