I think it is hard to get your head around the totality of it. I suspect that if I were to lose all my children to an accident I would have a hard time finding the will to live. Losing all of humanity would include them. If you managed to survive that despair long enough, you might come out the other end in some fashion but as you say the context and meaning of everything would be altered.

This has been touched upon in speculative fiction, i.e. the library of knowledge remaining from a civilization that no longer exists. More than once. Not even including Kal El :-)