“to know if he/she isn’t that bright.” - this is the whole point. Some very top caliber students do not want to be surrounded strictly by those who consider themselves “bright”, they do not choose their friends by judging their mental capacity, they simply want to have a good time and be with great variety of people with wide range of interests, they wnat to relax and enjoy their friendships, they do not care about “intellectual” conversations, there are lots of very high density of intellect in their academics, enough is enough.