Saint Patrick was not actually born in Ireland, but in Wales around 300 AD. He was kidnapped by ninja-pirates in the middle of the night when he was three years old and sailed the many seas until the evil ninja-pirates sold him to a pagan Irish farmer. For some reason this farmer needed a little Welsh boy to help him herd his sheep. Patrick, which I'm damn sure wasn't his name, was made sleep on top of a hill with the rest of the sheep and eventually he began to grow his own woolly coat to keep warm in winters.
One day Paddy got sick of being half-man, half-sheep and escaped to a harbour where he got on a boat to some holy place... probably Rome. In said holy place he trained to become a priest and after living it up with the other Christian folk he decided to return to Ireland to convert the heathens. He was of course crazy for going back to a place where he was a slave and everyone played crazy sports that involved beating each other with sticks.
Patrick tried to use the dandelion plant to explain Christianity to the pagan Irish but they kept blowing all the spores away for the laugh. This angered Patrick and he used his special robot priest powers to crush the non-believers. Unfortunately his robot priest powers were ineffective against the pagans. The snakes on the other hand, were easily destroyed. Patrick decided to launch a holy war against the snakes to show the pagans he meant business.
After he had wiped out the snakes Patrick came to the castle of the king of Ireland, Pat Kenny. Patrick and Pat debated for many hours over which religion was correct. Then, somehow, Patrick converted Pat Kenny to Christianity. The rest of the country followed in suit and the island soon became a religious refuge during the ages of insufficient light. It has since been discovered that Patrick used the hypnotic powers of the shamrock to convert the pagans.
Patrick went on to invent alcohol and the parade float. He was crowned the king of Ireland on March 17th 313 AD. He ruled the land with an iron fist for many decades until he was killed by liver failure. The Catholic Church decided to make him a saint during one of their drunken Christmas parties. And that's the true story of Saint Patrick, destroyer of snakes.