How To Tell A Man From A Boy (Part 4 - Myself). If you don’t know yourself as a man you will not know your values or terms, and end up being an indecisive push-over. Men know who they are and what matters to them. They can say “No” to a woman in a loving way, yet with certainty. They have a backbone and you can respect them. That is healthier than a people pleaser guy who slowly becomes passive aggressive and resentful because he can’t say no.