Reader and online friend Alexis raised an interesting point. She wanted to know if Ireland celebrates St Patrick's Day in a similar way to America.
From what I can make out St Patrick's Day parades happen as bonding rituals outside of Ireland as a way for people of Irish decent to celebrate not only St Patrick's Day but to remember and celebrate their link with Ireland.
In Birmingham, my home town, there's a fairly big St Patrick's Day parade and much Guinness is drunk all over the UK in commemoration of the day. My wife is Catholic so it's a fairly big deal in our home. Though we often celebrate St Patrick's Day in the company of an atheist and her Sikh boyfriend!
In Ireland they look askance at things like dying beer and pet dogs green as I am led to believe sometimes happens in America. I think they take it a bit more as a serious religious festival, though do know how to party. As I know to my cost having had to help a very dear but sadly departed old Irish friend drink a large amount of wines, beers and spirits that she found in her cupboard. A couple of years ago we drank Champagne at least 40 years old with the price on it in Pounds, Shillings and Pence, the old currency not used since 1971 when we went decimal!