I was on a training exercise once and late one evening while I was wrapping up some paperwork and chatting with a buddy a company commander came in and sat down next to us. He interrupted our conversation to ask us when we planned to get to bed. There was a shift change coming up and I wanted to be there to provide some continuity so I told him that I was going to be awake for another hour or so.
The commander scoffed in mock disgust and said, "Well, since I actually care about my Soldiers, I'm going to go to bed right now."
The look of confusion on my face showed that his comment had the desired effect. He went on to explain, "You guys are leaders. Your Soldiers depend on you to make good decisions. If you're exhausted, you're going to make shitty decisions and get your guys hurt. We owe it to our Soldiers to have a clear head and getting enough sleep is critical to that."
At the time, I had my doubts about his point, and to a certain degree I still do. But he wasn't entirely wrong either. If we spend all our time working for and taking care of those entrusted to our care we'll get worn down and become unable to perform at the level that we ought to. The level that we owe those we care for.
In failing to care for ourselves, we'll end up failing those we love. Yes, there's a line beyond which taking care of ourselves becomes selfish and ends up being self-serving. You've got to find that balance where you're taking care of yourself enough that you can then turn around and take care of your family.
It's easy to feel guilty about taking care of yourself. You might think, "Here I am going fishing with the guys while my wife is juggling three kids. I'm such a dick." Now, if you do this every week, then you're probably right, but if this is something you do every six months, there's no reason to feel guilty about it. In fact, you should feel guilty if you don't take care of your self properly.
Take care of yourself so that you can take care of your family.