Young OG

A young man who's wise beyond his years. He's been around/seen some things. He has the knowledge and wisdom of someone much older than him due to his life experiences.
A young person with a lot of wisdom.

Jamie: Wow I didn't know the CEO is only 25 years old

Sarah: Yea i can't either I guess he was just mature for his age

Jamie: Yea a real Young OG