What does Christopher do to the man in the station who ways, “You look lost”?

From the text:

And a man came up to me and he was wearing a blue jacket and blue trousers and he had brown shoes and he was carrying a book in his hand and he said, “You look lost.”

So I took out my Swiss Army knife.

And he said, “Whoa. Whoa. Whoa. Whoa. Whoa,” and held up both his hands with his fingers stretched out in a fan, like he wanted me to stretch my fingers out in a fan and touch his fingers because he wanted to say he loved me, but he did it with both hands, not one like Father and Mother, and I didn’t know who he was. And then he walked away backward.