I even dried some in the pages of our guide to Ireland. Apparently, according to the website of eircom.net I found out that the shamrock dates from 1571 and was worn as a badge to be worn on the lapel on the Saint"s feastday. The shamrock was used as an emblem by the Irish volunteers in the era of Grattan's parliament in the 1770's before 98 and the Act of Union. So rebellious did the wearing of the shamrock eventually appear, that in Queen Victoria's time Irish regiments were forbidden to display it.
Other facts: the the shamrock symbolises the Trinity to Christians as one God but three Persons being God the Father, the Son and the Holy Spirit. St. Patrick used the shamrock to illustrate this meaning in his teachings. The druids believed that the shamrock was a sacred plant and the number three was a mythical number in their religious practice. They believed that the number three was a magic number. It multiplies to nine, which is sacred to St. Brigid. Three signified totality: past, present and future, sky,earth and underground. Everything good in Ireland comes in threes. Three accomplishments well regarded in Ireland are a clever verse, music on the harp, the arto of shaving faces.
So, now we are all the wiser. I hope on the 17th of March you will wear your green proudly.