Einstein once said that "The only incomprehensible thing about the universe is that it is comprehensible." To put it simply, why is the universe understandable?
"St. Thomas Aquinas' arguments for the existence of God based themselves on the perception that there is an ordering within nature, which requires to be explained. Equally, the fact that the human mind can discern and investigate this ordering of nature is of considerable significance. There seem to be something about human nature which prompts it to ask questions about the world. And there seems to be something about the world which allows answers to those questions to be given."
Mathematics gives us a further insight. Mathematics is a pattern creating and pattern analyzing endeavor. Some of the most beautiful mathematical patterns dreamt up by mathematicians turn out to be true in the physical world. Why is this so? Because there is a congruence between the reason experienced in human mind and reason experienced in the created world. (John Polkinghorne) There is also a congruence of the human mind and nature in discovering its laws. Donald Mackay said that "The laws of nature we discover are coedifications of that activity of God in it normal manifestation."
Likewise, the sense of beauty we experience resides in the ability of the mind to see pattern, order, harmony and purpose in the created world. We see beauty in a flower or an insect because of its orderly arrangements of parts with a function and a goal.
Wisdom pervades the created world because God's has applied His knowledge in the internal and external ordering of creatures thus creating living unities combined with a certain freedom which allows creatures to react to environment and form relationships. This congruence between the human mind and the universe is a reality because God is the creator of both and in his wisdom harmonized the two for a purpose which he foresaw from all eternity.
Beyond these observations is the fact that the human body/brain is literally made up of star-dust meaning that its elements were born during the evolution of stars. Further, our ability to form universal ideas and to reason transcends our brain functions because God made us in his image and likeness, that is having intelligence and free will.