What forces (people, places, ideas) play a role in shaping Siddhartha's journey?

As the song goes, "Three is a Magic Number" in religion,
literature, and philosophy--and for good
reason.

Siddhartha can be divided into
three parts:

In part 1 (chapters 1-4), Siddhartha could
have gone to school, been a student and pampered member of
the upper class, but he rejects intellectualism alone as
the way of finding wisdom.  He also abandons his family, choosing instead his shadow
Govinda as partner in his religious
journey.

In part 2 (chapters 5-8), Siddhartha could have
been a wealthy merchant: he owned a house and possessions.
 Also, he has a lover, Kamala, who complements him even
better than Govinda.  Yet, he rejects the world of the
senses by leaving her
bed.

In part 3 (chapters
9-12), Siddhartha learns to listen to nature (the river)
and thereby achieve nirvana.  Siddhartha emulates the old
river ferryman Vesuveda here.  The old man is a mentor and
spiritual guru, yet he holds no spiritual title and has no followers.  The
river is a symbol of renewal, peace, and the spiritual
journey.  It's flowing water is symbolic of the inner peace that flows within the
spiritual man.

So, to review, here are the places, ideas,
and people of import:

1.  School -          
 Intellectualism -     Govinda

2.  Home / bed -    Senses
(Pleasure) - Kamala

3.  Nature / river - Nirvana -        
       Vesuveda