The CEO of

Explanation:
"We're amazing or the best at something..."
Example:

1. He's such a amazing singer, he's the CEO of singing.
2. She's always saying that she's the CEO of things - it sounds like she's really bragging!
3. I wish I was as good as her at painting. She's the CEO of art!

Diary:
The fight between my brother and me taught me to keep cautious of our psychological boundary of self. I'm grateful to it.