He's 100% right about the positive effect bjj has on your attitude and outlook, in addition to social interactions. It engenders humility and self-confidence at the same time.
I kinda think a lot of comedians would do well with BJJ. Starting BJJ is probably a lot like starting stand up comedy I imagine: Taking those steps to get on stage, bombing, getting booed, heckled, etc... and going BACK over and over to get better takes a certain amount of grit.