I've known a number of SOF (Special Operations Forces) guys in my life, and to a man they were the furthest thing from braggadocious. They're well aware of their abilities, and don't need to seek trouble. Most are wiry as opposed to musclebound ... picture the sculpted physique of a professional rock climber. They lead by example, not by barking commands, and are fully devoted to the mission and the team. Their training is much more than physically demanding, as it requires a psychological and emotional discipline that is either buried deeply within, or doesn't exist.