Young people are spoiled. Spoiled by the lack of responsibility, boundless energy, and the naivete to venture boldly down any given path. The aged are spoiled with wisdom, avoiding futile forays, and handling responsibility efficiently, which is necessary given the lack of energy. Its too bad you cannot get these life advantages in tandem.
Starting a family and then working to support them is sacrificing selfishness. It is well worth what is given up, but it is easy to forget defining characteristics, habits, and interests of the man alone.
I communcate with my family daily; usually by email, often by telephone, and sometimes by videoconferencing (Skype). This still leaves, what seems to me, anyway, an enormous amount of time to spend by myself. Reading comic books, writing poetry, mastering Kung Fu, collecting scorpions, whathaveyou. Some people make new friends, and spend their waking moments drinking coffee in the company of their new D-BFF (deployed-BFF). In these 4 decades though, I have made plenty of friends, and right now, I prefer to spend time with myself - the me that I haven't seen much of since the 10 years of medical training and kids started. And in between private attempts to impersonate Dave Matthews on the Persian guitar I have (so far) commondeered, or mastering the eagle pose during my late night physical fitness, there is (perhaps, dangerously) sufficient introspection time, during which I have drawn through 2 or 3 steno pads a complex soup of matrices, lists, ideas and doodles.
That is the way deployment to this place is, at least if you can keep your head square. You work like mad. To exhaustion. You see things that will destroy your faith in humanity, if you let them. But you don't because you cannot. So, you compartmentalize the horror. Leave that when you go home to your trailer. Take the time you have with yourself and capitilze on the beauty of life. Buff and polish your body and soul, you must. Use the terrible suffering you witness to give the relative ease of your life perspective and lead you to greatness. That, or kick back with your D-BFF.