I don't have an Irish Heritage, or at least not much of one. There is a fairly large Irish contingent where I live but there are equally as many people of German and Italian descent, as well Latvian, Asian and many others. But for some reason, I really like St. Patrick's Day. It goes along with my love of the color green, the high school my kids attended mascot was the Irish, and I have some cousins that are Irish Dancers. I like bagpipes (once or twice a year.) You may have noticed that I have quite a patterns that are inspired by Ireland and Scotland. So... I may not have a really strong reason, but I do like all things green and all things Irish!
My latest pattern is the called the Shower of Shamrocks. It is a slouchy stocking hat knit in the round using stranded color work - AND - it is free until St. Patrick's Day.