 Why is Rikud oddly satisfied about Crifer's limp foot?
Every day for a week now, Rikud had come to the viewport to watch the great changeless sweep of space. But ever since the engines somewhere in the rear of the world had changed their tone, from the steady whining Rikud had heard all twenty-five years of his life, to the sullen roar that came to his ears now, the feelings had grown. Rikud knew that something which he could not explain had entered the elder man's head for a moment, but it had departed almost before Chuls knew of its existence. Rikud, for his part, wanted to get back to the viewport and watch the one new bright star. But something soft had cushioned the impact—something which had come into being just for the moment and then abruptly passed into non-being again, something which was as impalpable as air. Rikud had been stopped in this action, although there was no real authority to stop him. Much of this Rikud could not understand, but he knew enough to realize that the reading machine had sided with the people against the elders, and it said the people had won. He could see the look of easy contentment on Chuls' face as the rays fanned down upon him, bathing his old body in a forgotten magic which, many generations before Rikud's time, had negated the necessity for a knowledge of medicine. Rikud often thought of his own death, still seventy-five years in the future, not without a sense of alarm. Under the tube at Rikud's left lay Crifer. Rikud was guiltily glad when he saw Crifer limp. Now Crifer said, "I've been reading again, Rikud." But if he wasn't reading himself, Rikud usually went to sleep. This was a new thought to Rikud, and he propped his head up on one elbow. "You know," Rikud said, sitting up now, "the stars in the viewport are changing." "Astronomy says some stars are variable," Crifer offered, but Rikud knew his lame-footed companion understood the word no better than he did. Over on Rikud's right, Chuls began to dress. Rikud looked and looked until his eyes teared and he had to turn away. Rikud couldn't remember, and he suddenly wished he could read Crifer's book on astronomy, which meant the same as stars. Presently Rikud became aware that his eyes were not tearing any longer, and he turned to look at the viewport. Change— "Won't you eat, Rikud?"
 It's evidence that imperfections still exist, and validates Rikud's feelings.
 It's new and interesting. Rikud is tired of the regular.  It means that people can hurt, which Rikud has an interest in.  He dislikes Crifer, and enjoys the fact that he is stuck with an anomaly.  It's evidence that imperfections still exist, and validates Rikud's feelings.