What reference is made to a soldier?

From the text:

Anyhow, I slept most of the way. When I woke I was leaning against a soldier; he grinned and asked me if I’d come from a long way off, and I just nodded, to cut things short. I wasn’t in a mood for talking.

There is only one mention of a soldier in the novel, The Stranger. The above quote gives no indication as to the time period of the story.