How did the childhood experiences of Siddhartha Guatama (Buddha)lead
to the spiritual practices of his time?

We are told that knowing well what was in store for his son, his
father tried his best to shield him from all possible spiritual
contacts and influences by surrounding him with pomp and luxury and
providing all material comforts, so that when he grew up he would
become a great ruler. He built three palaces for his son with all the
comforts and amenities and arranged for his training in in martial
arts and education in various subjects necessary for conduct of state
affairs. We are told that despite of these arrangements the young
Siddhartha was still drawn occasionally into philosophical and
contemplative thinking during which he would suffer from deep despair.

When he reached the age of sixteen he was married to a beautiful
princess called Yashodhara. She was the daughter of a Sakya Chieftain
called Suprabuddha. He had a son through her by the name Rahula. We do
not know much about his family life, except that he cared for his wife
and spent considerable time in her company. We do not know whether he
had any liaison with some other women too. Yashodhara was probably a
very dutiful wife, who might have suffered later in life when the
Buddha finally left her.

During this period he went through four strange experiences which the
Buddhists refer as the "Four Noble Signs". They changed his thinking
completely and brought a fundamental change in his attitude towards
the life he was leading till then.

The first of these signs was the sight of an old and decrepit man.
This made him think about the decay inherent in all life. The second
was the sight of a sick and ailing man. This made him think about the
suffering inherent in existence.

The third sign was the sight of corpse lying in a bier. This made him
think about the transience of human life and need for liberation from
the very experience of death. The fourth was the sight of a meditating
monk, who had renounced the worldly life and was leading the life of a
monk. It reminded him of the possibilities of spiritual life lying
beyond the boundaries of his own materialistic life.

These experiences prompted the young Siddhartha to review the life he
was leading till then and change it if he could. He was overwhelmed
with a sense of grief and compassion for the troubles of the mankind.
He decided not to rest till he found suitable answers to the questions
that were troubling him for some time. His son Rahula was just born
then, as if circumstances were making it a little more difficult for
him to leave his wife and worldly life behind.

http://www.hinduwebsite.com/buddhism/buddhaslife.asp
http://en.wikipedia.org/wiki/Gautama_Buddha