I would have to go back and read my old copy of "Surely You're Joking Mr. Feynman" but I recall the story about his participation in the Manhattan Project. The way the story gets told, he quickly gained a reputation as someone who was unafraid to tell the older physicists when their ideas might have flawed thinking in them, and in return they would seek him out as someone fresh out of Cal Tech, trained in all the latest thinking, who could help them stay on track. So he quickly gained a reputation as a brilliant young hotshot, not to be taken lightly, even among the most esteemed Physics minds of the time.