Fahrenheit 451: an ending that makes you think

Although it seems that the obvious interpretation of the ending of Fahrenheit 451 is that humans will always destroy their world, but the knowledge must be retained in order to build a new, even stronger one, I find this ending sad. It is powerful, but I see it as really sad. It seems that the ending is Guy Montag struggling to find knowledge, and eventually discovering that his life has no meaning. I find it interesting that his life has no value; this kind of means that no one's life has value. But, although no single person's life has value, the collective life of those who preserve knowledge is priceless. Without the group of nameless individuals who individually don't matter, their group is the reason the Phoenix of their society can be reborn.