 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. 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." Over on Rikud's right, Chuls began to dress. Presently Rikud became aware that his eyes were not tearing any longer, and he turned to look at the viewport. Rikud turned again to the port, where he could see nothing but an obscuring cloud of white vapor, murky, swirling, more confusing than ever. The old man turned and strode off down the corridor toward the dining room, and Rikud was glad to be alone once more.
 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.