its so that stupid people can feel better about their lives.
those I know who are successful, always admit how stupid they are, they admitted it early and hence invested in the workarounds, diff paths, loopholes which made them successful.
Yet the those acquaintances i know that assume (incorrectly) the most, spread the most gossip, are also the most behind when it comes to their professional, financial, personal lives as well as health.... are always boasting out loud how smart they are.... and that they know 'everything'.
Funny enough, this 'smart' person, amongst those who know him best always use him as the prime example of exactly what not to turn into in life.
such smart, poetic irony.
I think it goes like this:
The average person isn't very smart, which means that half the people are stupider than that.