The story mentions family and he did command a ship but a theme is a general, underlying thing that shapes the story itself. The navy guy wouldn't be feeling any of this if he hadn't seen suffering and violence and stress during his time at war. So it influences his behaviour with his family/friends at home. Therefore, the theme of the story is about the importance of life decisions. He no longer views these minute things (like vacation spots and home decor) as important.
