What I have have come to realize and know for sure is that my students and clients could give a crap about what I know, until they know exactly how much I care. My good buddy Rick Church taught me that and my Coaching and Training reinforced it. If I knew 1/2 as much as I know now 15 years ago, WOW!
But that is just experience, and life. Most training doesn't prepare you for the actually experience you get when you're thrown into the actual setting. What I know now, for sure, is that a positive compliment("Hey, Great depth on that last rep"), A High-5, Sweaty Hug or even just a smile goes miles in showing my students and clients what they mean to me. And how important they are. This is for sure, the one's that believe, will run through a brick, push through a plateau, perform one more rep of that weight they didn't think they could get, just because they knew how much I cared about them.