Human brain did not evolve to discover the way nature works, I think. Human species is just one of the several thousand species known to exist. However, we have a large brain and certain abilities which other species do not possess.
Just like there are limits to everything we can do, there should be limits to what we can know. Of course, there is the question that what is total truth. There are so many happily living species who do not worry about these questions, and know nothing about the knowledge human beings have gained.