Aristotle begins the Metaphysics with the famous, "All men by nature desire to know." (Or, in deference to the more sensitive among us, "All human beings by nature desire to know.")
When he says "by nature," he means in sum that our desire to know is a desire to exercise some inborn quality in us. We're born to operate this way: to use our minds to the fullest extent. We want to know things not because we chose to want to know--it's not a matter of convention. Nothing forces us to want to know. It is our nature to want to know true things.
In fulfilling this desire, we become fully human. That is, we exercise our human nature. For Aristotle, as for most of the philosophical tradition, reason and art distinguish human beings from other animals. That's why studying and seeking the truth matters: it's this action that practices or exercises that which is most fully human about us. It makes us more human.
That's also, then, the basis for why we study liberal arts (which seem so useless on the job market): having practical knowledge is useful, but to study the highest truths simply for the sake of knowing truth answers a basic call of our human nature. In Aristotle's terms, to study the less-practical questions is to learn the why of things. A mechanic can know that the car will run on gasoline but not on Diesel; a scientist will know the why. On the moral level, the statistics major can know that being cheated on hurts; the contemplative soul wants to know why.
Knowing the why is wisdom (sophia). The lover of wisdom seeks to know the why. Every human being has an inbuilt desire to know. If we cultivate that desire rightly, we will love wisdom and seek it always.