Siddhartha Gautama was a prince who lived a life of luxury, He was given everything so he didn't have to leave the palace.
One day Siddhartha decided he wanted to see the outside world, his father, the king, however, didn't want him to see any sickness. So he ordered all sick, dying and poor people to a separate place so Siddhartha could go out into the city. However Siddhartha saw a sick man and an old man.
He also saw a funeral and a poor man. Siddhartha Gautama had never seen any of these things before and was confused.