says "A lot of people I talk to think they're intelligent. "
I don't know. I don't like intelligence contests or beauty contents.
What do I like is the excitement of thinking about things and finding new things or understanding what other people found in their own excitement.
I don't think you can measure (or even define) intelligence as you can measure money, and, in particular, "twice as much intelligent" is meaningless.
I think that, for example, the great results in mathematics are driven more by curiosity and persistency than by intelligence.
Of course intelligence (whatever it is) helps a lot. But without curiosity and persistency, it is useless.
Also, there is another rather important factor. Some people just can't stop thinking. This also helps.