The title of this post is taken from Taleb's book Fooled by Randomness How are there so many people with lots of money who are not very intelligent? The answer is simply: luck.
If you have 300,000,000 people playing the stock market and their stock choices can be modeled as complete guessing, then after a binary event outcome 150,000,000 are going to come out on top. And from those 150mil, 75mil will win again. This repeats a few times and in the end you're left with some very rich people who have done nothing but guess. Everyday some bloat comes out of the casino as a winner.
So then you have someone who has won n times, is fairly wealthy, and falsely assumes he will win n+1 times. There's tons of men in suits with lots of cash, and if you're an investor in people and relationships it's your job to determine which one of these men came about their wealth through luck and which ones came about it through a refined process. Especially when you're in the stock market world.