Are a lot of men secretly sad?

I (F) work with a guy who is very successful. He’s high up in the company, leads a team. He’s in a relationship. On paper it probably seems like he has it all. One day we were talking and he mentioned that he’s often sad. I was a bit surprised because you wouldn’t initially think it. Made me really feel for him.

Edit: thank you for all of the honest responses. This hurts my heart! Sorry you are going through this.