Mensa is for people who grew up in gifted programs being told that they will achieve greatness just because of the one test they scored hight on, and then they amounted to nothing, so they need a place where they can tell each other that they are unsuccessful only because they are so much smarter than everyone else around them.

High IQ people who manage to do something with their life usually have more to be proud of than an IQ test they took decades ago.