Ah. There is more to life than behind the palace walls
In the 6th century, Siddhartha is talking with his friend in Gupta, India and his friend has to go because there is work to be done in his village. Then Siddhartha goes with because he is curious.
OK, I guess
Avoid all physical comforts and pleasures.
When he got to the village he found a dead man, a beggar, and a sick man. He asked his friend if those things could happen to him and his friend said yes.
He sees there is more to life than just behind the palace.
That's the 4 noble truths.
Ah, I see.
He then traveled and tried to learn from other holy men. He almost starved himself to death by avoiding all physical comforts and pleasures as the holy men did.
One day Siddhartha thinks of a childhood memory and then reaches the highest state of Buddhism, Nirvana. It refers to the "blowing out" of the flames of desire. Then Siddhartha had become Buddha or the enlightened or awakened one.
After he became Buddha he started teaching others about Buddhism. He taught them that Buddhism teaches the 4 noble truths. They say that life is suffering, that desire and want causes suffering, that eliminate want to eliminate suffering, and that you have to follow the eight fold path.