Question for other dads: When do you start talking about the "hard stuff"?

My oldest is 11. He's starting to notice stuff - asking questions about why people are mean to each other, asking about my job and money stuff, getting curious about body changes.

I want to be honest and age-appropriate but idk where the line is. What conversations are you having with your 11yo or 12yo? How do you approach it without making it weird?