Why does Coelho open The Alchemist with the modified myth of Narcissus? What might he be suggesting about how we perceive ourselves and the world?

In Paulo Coelho's The Alchemist, it
is ironic that the author prefaces his tale with a story about Narcissus, perhaps the
first ego-maniac.

I find it curious that Coelho uses the
entire version of the Narcissus tale here—for the rest of the story is so
much about being one with the universe. I never get the sense that
the story promotes self-interest while ignoring the rest of the humanity. Santiago is a
young man with manners. He listens to Melchizedek simply to be polite even when he
thinks the "King of Salem" is just a rambling old man. He is not greedy. He
does look for treasure, but when he is robbed, he is not so eaten
up with the desire for riches that he pushes relentlessly on. In fact, he is ready to
stop searching for his Personal Legend and the treasure, and be
satisfied caring for his sheep for the remainder of his life. He feels the same way when
he meets Fatima. For her, he believes he needs nothing
else.

"I want
to stay at the oasis," the boy answered. "I've found Fatima, and, as far as I'm
concerned, she's worth more than
treasure."

It seems to me
that the story of Narcissus and the lake shows that everyone is very much the same.
Narcissus is said to have been punished because he was such an egotist and so unkind. He
drowns, and then the lake becomes salty with tears. We expect it is
because the lake cries for the loss of the conceited Narcissus. However, the lake is
just as guilty as Narcissus was: she could only see her beauty in
his eyes, missing anything significant about him.

It would
appear, then, that the story says we are all in the same boat. We all can see only that
which pertains to us: it seems a sad commentary that all mankind is
described as being like Narcissus.

I must admit, however,
that I do not know if I completely understand why the alchemist finds it such a "lovely"
tale. Perhaps it is because of the simple-mindedness of the Narcissus and the lake— that
they foolishly lose sight of what is important in life, when the answer is there for
anyone willing to look beyond the end of his/her own
nose.

The alchemist
notes:

There
is only one way to learn...It's through
action.

Perhaps the alchemist
sees the tale as "lovely" in a trite and nonsensical way—a whimsical story with a
surprise ending. For had Narcissus acted upon anything outside of himself, his fate
would have been quite different.