One of the most important lessons we learn from the pilot is to look beyond the corporeal. We learn in the very first couple of chapters that the pilot struggled in his life because he saw things in a way that others could not see them. As we see from his "Drawing Number One," a person is only able to discern that it is a picture of a boa constrictor from the outside digesting an elephant if one pays close attention and notices the small details, such as the eyes of the snake and the shape of the shape of the elephant. Since the elephant is not truly seen, except in silhouette form, we see that this drawing is a lesson of seeing things beyond the obvious and beyond the corporeal. In addition, we learn that the pilot has shown his drawing to people throughout his life in order to determine if he or she is a "person of true understanding" (Ch. 1).
A second lesson we learn from the pilot is actually one the pilot learns from the prince himself. The pilot learns that, while he has always had an appreciation for the things unseen, he too has allowed himself to get swept away by things of less importance, just like the grown-ups. The prince has reached a very strong understanding that the things that really matter are what can't be seen, such as love and faithfulness. At one point the prince begins to worry about whether or not his drawing of a sheep in a box would eat his flower. The pilot replies that he is "very busy with matters of consequence!" (Ch. 7). The prince responds with a rational argument that portrays his love for his flower, even though he cannot see his flower because she is far away on one of millions of stars. He further argues that just the mere thought that his flower could be threatened by the sheep is a matter of great consequence, as we see in his lines:
If someone loves a flower, of which just one single blossom grows in all the millions and millions of stars, it is enough to make him happy just to look at the stars. He can say to himself, "Somewhere, my flower is there..." But if the sheep eats the flower, in one moment all his stars will be darkened...And you think that is not important! (Ch. 7)
Hence, we see that the little prince's speech teaches that what is truly important are the things unseen. In addition, the pilot accepts and teaches this lesson himself when he lets his tools drop from his hands in order to comfort his prince, the one he loves, showing us that what really matters are the things unseen, such as love.