A true captain is a very humble person. Attitude is more important that anything. Being 23 years old has nothing to do with it, maturity and humility has everything to do with it. Anyone can be taught how to pass a 121 checkride, it is another thing to flow with the constant change on the line. That takes time and experience, I hope the 23 year old captain takes all the advice that he can get. As for safety if the bad decision gets him in a jam his quick reactions and hand eye coordination with usually get him out.He has a lot to learn and as an FO you have to go the course with him and learn with him.