what did thomas learn about himself the evening he ran into the maze before sundown

As he runs back Thomas realizes two things about himself. First, he has navigated the Maze without even thinking about it. He does not falter in his path once. Second, he is in great shape. He has recovered from his harrowing exhausting experience the day before. Thinking about the speed he has been running and the time it has taken, he has probably run the equivalent of half a marathon. As he runs he can appreciate the size of the Maze. It runs on and on for miles and miles.