One way intelligence manifests itself is through the ability to score well in an IQ test. Another way is through the ability to make an impact on the world. But I think another really strong characteristic of intelligent people is their tendency to lead a rich inner life. I get the strong impression most people go about their business without ever really thinking about how incredible it is that the universe not only exists but contains (at extremely low density) sentient beings capable of reasoning about it. Being one of those sentient beings is a remarkable stroke of luck. Intelligent people recognise that and celebrate accordingly.