And you need not show that you mind When the others come in after hunting To gobble their muffins and eggs. (3-5)
We feel that the soldier is convalescing (i.e., recuperating) at home, but the speaker doesn't actually say the words "home" or "house." This omission is significant, because it suggests that, in a way, the soldier is homeless—isolated and alone, even though he's back from the trenches. He's not socializing or eating, maybe because he doesn't feel comfortable. His home doesn't seem like a place where the soldier can do home-y things anymore. War has changed all that.
And people will always be kind, As you sit on the terrace remembering And turning your face to the light. (8-10)
The soldier sits on the terrace and turns toward the light, but he can't really see it. His loss of vision, and the fact that the terrace will no longer be what it once was (a place to look at a beautiful view) suggests that his home has become a totally different place.
For they'll know you've fought for your country And no one will worry a bit. (14-15)
The speaker explores a different kind of home here, the home that is one's neighborhood or country. The people in this larger home, it seems, don't treat the soldier like a family member. They realize he's a soldier, but they don't quite realize what that means—what he's seen and experienced. And that's really the problem here. There's this gaping divide between who the soldier is post-war, and who these folks think he is—his prewar self.