IME, what differentiates men from boys is the size of their empathy.
I’ve been looking after myself since my parents divorced long before I graduated high school and I’ve been self-employed most of my life. I’m still a boy in my heart though.
I remember when I traveled as a child theme park personnel used to call me ‘boy’. They still called me ‘boy’ after I became a teenager and, later, a young man. And then suddenly they were calling me ‘sir’ but I didn’t notice exactly when the passage occurred and I no longer cared. “I guess I’m not a boy anymore,” I said to myself and moved on.