Oh, the wastes! The magnificent wastes! When I was a lad I knew a man who visited the wastes and brought back such beautiful things! Real salt from the dry riverbeds, pieces of rubber that would burn for hours and give us such marvellous dreams! One day I’ll earn enough to take you to the wastes myself, young one. One day.

He’s not joining the conversation because they’re strangers who just happen to be riding the same public transit as him.