I remember reading about orphanages where the children never get touched in a loving way. They fail to thrive to their potential and there's no physical reason for it. No one wanted to touch those kids, they took care of them. Fed them, changed them but the little touches don't happen, or very rarely happen for those children.
We need those little touches. Without them we shrivel up and become a shell of ourselves. We don't even really know that we need them because the act itself doesn't really register. When you sniff your newborns head you don't do that because of any reason other than you love the baby smell. When you put your arm around your parent you do that because your body needs to feel a connection. And when you don't have those little touches you shrivel up, and you don't even really know why. You don't think to yourself "I wish my lover would stroke my face." or "I wish my son would put his arm around me."
Sometimes we recognize the urge to give a little touch and stop ourselves. Why do we do that? Is it fear of rejection? Is it because we don't want to give someone else the power to know we care? It doesn't make sense, but we do it don't we? Maybe sometimes it is easier to not give in but at what expense?