"Never think you're the smartest guy in the room... unless you're the smartest guy in the room" - Neal Caffrey
I was thinking about the saying, "‘Happiness is reality minus expectations" and I was thinking that it applies to intelligence also. In this essay, I'm talking about intelligence as an abstract idea, not something that can be precisely measured.
Functional Intelligence = How Smart You Really Are - How Smart You Think You Are.
When you think you're smarter than you actually are is when you get into trouble. You try to fool other people. Ponzi schemes, such as Bernie Madoff and "allegedly" FTX / Sam Bankman-Fried (SBF) are classic examples. They initially made money for their clients but instead of admitting when they had a loss, they covered up the losses in the hopes of making the loss back. They were arrogant enough to think they could fool everyone.
On the other hand, less intelligent people who know their limitations work hard to overcome them.
Not overestimating yourself is the biggest signal of intelligence.