In Coelho's The Alchemist, the lake's perspective and that of Santiago are very different.
In the story of Narcissus, the young man is obsessed with himself. He worships the image reflected back at him from the surface of the lake. When Narcissus dies, the lake cries because she will no longer be able to see her image reflected in Narcissus' eyes. Both the man and the lake are selfish and self-absorbed. Her selfishness is evident:
I weep because, each time [Narcissus] knelt beside my banks, I could see, in the depths of his eyes, my own beauty reflected.
Santiago may begin the story searching for material wealth, but soon he is looking for the truth of the world. He looks for ways to better know himself and understand his place in the world. He is by no means selfish. When he is confronted by various characters in the story, he listens to what they have to say, and may question their reliability or motives (such as the gypsy), but he faithfully considers each bit of advice or knowledge gleaned from these interactions and comes away with something valuable that enables him to continue his search for his Personal Legend.
For example, when Santiago meets Melchizedek, he first believes the old man may be crazy (or working with the gypsy), but he is not rude even though the "King of Salem" is dressed in common attire and (as far as Santiago is concerned) looks nothing like a king. "The boy" listens to the old man and seriously considers his words of advice. These words ignite within Santiago the intrinsic desire to move forward.
When Santiago meets the Englishman, he does not reject the other man's methods in searching out his Personal Legend, although it is very different than Santiago's approach. The Englishman relies on books, while listening to nature and watching for omens doesn't help him at all. And although books offer nothing to Santiago in his quest for his Personal Legend, he never believes that his own way is the only way: he simply acknowledges that the Englishman's dependence on the written word does not work for him.
"Everyone has his or her own way of learning things," he said to himself. "[The Englishman's] way isn’t the same as mine, nor mine as his. But we’re both in search of our Personal Legends, and I respect him for that."
Santiago is robbed of the money he earned in selling his sheep. Destitute, he convinces a merchant to hire him to help sell crystal. Immediately sales improve, much to the surprise and delight of the merchant. At no time does Santiago act as if his need to return home is more important than the deal he strikes with the merchant. He is an honest worker. He is patient: he listens when the crystal merchant speaks of his dream to go on a religious pilgrimage, which he will now never have the opportunity to do. Santiago earns his keep, is a responsible employee, and learns from his time with the crystal merchant that he can move forward—although he previously believed he never would.
While the Englishman looks for a way to turn common metals into gold, Santiago comes to realize that even though he finds material wealth under the tree in the old churchyard at home, his real treasure awaits him in the person of Fatima. Discovering his Personal Legend is more important to Santiago than money.
Santiago's willingness to consider the ideas of others demonstrates that he is not selfish, while the lake is very selfish.