I'm curious...aren't you curious? Here's what I found out:

Had it not been for a band of Irish marauders in the fifth century, March 17 might've been plain old Maewyn's Day - because Maewyn wouldn't have changed his name to Patrick, and he likely wouldn't have become a saint. In fact, it wouldn't have been a Day at all.
But as it happened, a certain 16-year-old Welsh lad was kidnapped by those Irish marauders, and during the six years young Maewyn spent in servitude as a shepherd in Ireland he experienced a religious awakening, then spent years studying in a monastery. He took on a new name, Patrick, and a new calling - converting his countrymen to Christianity.
Interesting Fact:
In his Confessio, a spiritual autobiography, he writes:
So, how is it that in Ireland, where they never had any knowledge of God but, always, until now, cherished idols and unclean things, they are lately become a people of the Lord, and are called children of God.
Saint Patrick died on March 17 in the year 461, and this date was declared a religious feast day. Pretty cool huh!
HAPPY ST. PATRICK'S DAY TO YOU