It depends on what you believe to be valuable. The way I see it is humans were able to become so powerful because of their ability to interpret information and change their actions accordingly. Because knowledge helped us become the most powerful species, I view knowledge and truth as the most important things in life. On the other hand, there is something to be said about viewing happiness as the most important thing(I don't think it is). Would you rather have a happy life or one that is filled with worries and depression?