fortunot (noun, adjective): fortunate + not
As the phrase states, "luck of the Irish." Well historically the Irish people were actually not so lucky: invasion, exploitation, starvation, and weren't most of those who died on the Titanic of Irish heritage? Whoa. Fortunotsomuch. Thus perhaps the phrase is intended to be ironic. No matter how one interprets it, despite a history of fortunots, the Irish certainly are survivors. And they throw a good party too.
For every wound, a balm.
For every sorrow, cheer.
For every storm, a calm.
For every thirst, a beer.