The narrator is confused that everything is quickly getting back to normal. Why?

I think that after such devestation and near collapse of the human race, people seem to be rebuilding quickly. The narrator decides to go back to his house in Woking. On the way, he sees people rebuilding the tracks destroyed by the Martians, and this gives him hope for humanity. When he arrives at his house in Woking, he is shocked to discover his wife there. She faints from the shock.