It's spelled "Paddy", not "Patty."
Your attire should be more like this:
and a little less like this:
The phrase "Erin go bragh" has nothing to do with women's undergarments, and if the beverage you're drinking with your corned beef and cabbage looks like this...
...may the cat eat you and the Devil eat the cat. (traditional Irish curse. Yes, really.)
Stay safe everyone, and have a happy St. Patrick's Day.