Why is it such a struggle for a guy to be a gentleman? Or a boy to grow into authentic manhood? Men the struggle is real. Here is Eric Mason to explain what killed manhood from his book Manhood Restored,  

There was much more wrapped up in that piece of fruit in the garden than just a bad decision. With sin, there always is. We talk ourselves into thinking that sin is just a bad choice; it’s not. It’s much deeper than that for us, just as it was for Adam. When Adam chose willful rebellion against the law of God, he was choosing to forfeit his birthright by rejecting his calling to represent, be responsible, and enjoy his relationship with God, his wife, and the rest of creation. This single act placed in motion the initial and progressive fall of creation and its order, one whose effects still ravage every facet of the world today. We could speak at length on all things that were lost—peace, harmony, joy, order—these were put aside for temporary pleasure. 

Did Adam know the full implications of his choice? Probably not. But sin is like that. It blinds us to the consequences of our actions. We get so nearsighted when we see something we want to experience that everything else fades away. Adam chose to set aside his representation of God, responsibility for God, and relationship with God, and these things were lost because of the price of his sin. Although men and women are equal, their function in the fall was different. As the man, Adam is held responsible for it ( Rom. 5: 12). Sin entered through Adam and spread to men and women alike. When Adam sinned, all of God’s intentions for man fell with man. Peace and enjoyment of God and His creation was lost. The spread of God’s reign across the earth was lost. Dominion over the world was lost. The development of the undeveloped earth for the Lord was lost. Gone. 

Adam made this choice in the most perfect of environments. It would only get worse from there. As more people were born, after the fall in Genesis 3, they would be born without Adam’s responsibility, representation, and relationship, at least in the sense that God meant in the beginning. The definition of being an image bearer of God would be marred at the core of man’s being for millennia. Man would struggle and replace what was meant to be reflected as a sign of his relationship with Yahweh with himself and creation. Without a relationship with God to navigate and give value to responsibility and relationship, humankind would spiral out of control. 

Consequently, manhood was lost along with the rest of God’s original design for creation. Instead of responsibility, representation, and relationship, things like chauvinism, violence, passivity, insecurity, and addiction would characterize generation after generation of men in a continually increasing way. (Bold and italics are mine)