There are two kind of intelligence, one fluid and one fixed. But how I explain usually to other people, the ability to create using intelligence has two components, hard work and fixed intelligence. if you give both a value between 1 and 10, you can see why hard work sometimes trumps intelligence as potential. Imagine someone brilliant with 10 intelligence, but 2 effort => 10x2=20. While someone with 5 intelligence, but 8 effort => 5x8=40. So average hard working intelligence is twice better than unused potential. How is that looking for you? This is my Explain Like I'm 5 version.