It is frequently assumed that if we try hard enough, there are no limits to our understanding of the universe. As wonderful a thing as the human brain is, there is a finite number of neurons and synapses available to store information and inform decisions, just as we have a certain set of perceptual tools at our disposal*sight, hearing, taste, etc..
For example, we have no foundation in which to understand the electromagnetic sense perceptions of certain aquatic animals, because we have no analogous organs of our own. So there are limits to everything human, and that includes intelligence and the ability to understand. We may be as incapable of a deep understanding of the universe as dogs are of algebra, but we'll undoubtedly keep trying.