Tomorrow is St Patrick's Day, the recognition of the death of St. Patrick, who brought Christianity to Ireland. The day has evolved into a worldwide celebration of all things Irish and all things Irish-ish.
Got green? Wear it.
Got something to drink? Drink it.
The celebrations, were at one time, biggest in North America, and criticized for being commercial and promoting negative images of Irish people (i.e. heavy drinkers). While that may be true, it's also a time for learning.
Regardless, of one's religious beliefs, there is something poetic about the Irish explanation for the shamrock. The Irish use it to explain the Holy Trinity and the three petals represent the Holy Father, Son, and Holy Spirit (Holy Ghost). I always thought that it looked like three hearts, which kind of correlates with the explanation.