In honor of St. Patrick's Day, and inspired by a spate of Irish heroes in my latest run of contemporary romances, this month I'm celebrating all things Irish. First, let's talk about St. Patrick's Day.   For those who know March 17 only as a day of huge parades, green beer and public drunkenness, it should be said that St. Patrick's Day is actually a religious holiday - celebrating the death date of the most commonly-recognized patron saint of Ireland and commemorating the arrival of Christianity in Ireland.