Before Siddhartha Gautama was born, his mother (Queen Maya) had a dream of a white elephant entering her womb. Another special sign was when Siddhartha was 5 days old, a holy man came into his house for a feast; his future showed that he was going to become a king.
Therefore, he was protected from danger and anything disturbing in the world. He became the prince of India 2500 years ago.
However, one day Siddhartha was curious and slipped outside of the palace. He then sees what is known as the '4 sights': Old age, sickness, death and a holy man. The first three sights really shocked him and he started to wonder the meaning of life.
The holy man seemed very calm and had very peaceful even though he was just very rags holding a cup.
After this point, he gave up everything including is son and wife.
Finally, he sat under a Bodhi tree to mediate and had reached enlightenment after 49 days. Later, he was known as the Buddha and taught other people.