Can someone tell me how growing up without a mother can affect a man?

I have a friend that tries to put on a tought front and acts like he doesn't care but he has to he's human..could this have something to do with his upbringing..His mother left him really young to be raised by his grandmother..once out of 7 years I've known him..he expressed his frustration saying he would punch her if he met her again....could this be the reason he is so tough and can't admit he has feelings for someone? or am i looking in the wrong place..wait why am I looking? I guess I love this man..we're just friends.