A term that has it's roots in the ironic fact that the Irish are not that lucky at all. Originating from the 1800s, the "Luck of the Irish" referred to their bad luck, having throughout their history suffered famines and invasions that took millions of lives. When the Irish began emigrating on mass to the United States, Canada, Australia and Great Britain, to escape the Emerald Isle the phrase "can you believe the luck of the Irish" was frequently used.
John Lennon - If you had the luck of the Irish
You'd be sorry and wish you were dead
You should have the luck of the Irish
And you'd wish you was English instead!