The character in "The Scottish Prisoner" finds joy in his ability to remember lines from a play during his journey. This mental exercise not only entertains him but also provides a form of comfortable distraction as he navigates the trip.
As he recites the lines quietly to himself, he takes care to avoid making any loud noises that might disrupt his thoughts. This attention to his surroundings, coupled with his enjoyment of the play, enhances his overall experience during the journey.