Answer:
That he thought he doesn't have much longer to live.
Step-by-step explanation:
Based on this excerpt, we can conclude that Rajan thought that something was medically wrong with him and that he doesn't have much longer to live. That's why he started appreciating everything much more than he used to, instead of appreciating it either way. People around him wanted him to realize that, and decided to trick him. Despite it not being moral, it worked and changed the way Rajan viewed life.