Confidence, specifically self-confidence, is not something you will gain by osmosis, imo. Another person's confidence in his or her own abilities cannot and therefore will not translate into you suddenly having that same confidence in yourself that you yourself now have those same abilities in like quantity or quality as the one observed. The world does not work like that. Human beings do not behave like that. The source of self-confidence is the self recognizing within itself the foundation for confidence. That foundation, with respect to trading, will be your trading plan, which you know will yield consistently profitable results because you developed it and tested it through your own observations, but more importantly, your self confidence will come from, be bolstered by, and reinforced continually by your ability to follow your trading plan.
What does a trading plan look like? There is no standard, as far as I know. NoDoji's is 60 pages complete with illustrations. Mine is a few lines and a picture in my head, DbPhoenix can communicate his with just three chart images, and another poster has two chart print outs under a clear desk protector in front of his workstation - one with his rules for going short, the other for going long, and the rules for how he'll set his stops and profit targets. What your trading plan looks like is, imo, unimportant - it needs to look like whatever it must in order to give you the rules you will follow when you trade to assure yourself that over the long run, you will have consistently profitable results. That is where you will find the source for your self-confidence as a trader. Without it, there can likely only be recklessness and fear. And there is no way that someone else's self-confidence will overcome your own fear.