In Paulo Choelho's The Alchemist, why did the alchemist leave Santiago alone at the end to complete his journey?

With
regard to Paulo Choelho's novel, , my first reaction is that at the end,
Santiago must go on in order to fulfill his Personal Legendas as it is
hisand he must do it alone: it is his journey of
self-discovery.

Santiago has realized the connection he has to God, and the
powerful miracles he can perform because he is one with God. However, he must travel to the
Pyramids, which has been his goal all along, because of his dreams.

However,
when he arrives,...