Deep down in the Human Operating System is a need to impress people. Constantly. This is a hardwired behaviour, and hey, I can't help myself either.
Now that I'm a little older, I notice that truly impressive people don't need to tell me how smart they are. They go hard in the other direction. They're confident saying "I don't know". They ask me to review at their code, even though I'm an idiot. They ask me for advice, even though I'm a schmuck.
Perhaps that's how impressive people become so impressive. They treat every moment like an opportunity to learn, not an invitation to show off.