While it is speculative, as with much of what is "known" about St. Patrick, there may be a connection between Guinness and St. Patrick. While there continues to be debates about where St. Patrick was enslaved in Ireland, it seems likely to have been Ulaid (ancient Ulster), where the Magennises were one of the prominent families. The brewery Guinnesses are one modern branch of the Ulaidian Magennises. Thus, it is not out of the question that the ancestors of the Guinnesses at least belonged to the tribe that enslaved St. Patrick. The enslavement ultimately resulted in his mission to Christianize Erin. Thus, it seems entirely to toast St. Patrick with a pint of Guinness.
After a hard day at work some of the guys head to the local pub.
The Mexican guy says "Give me a Corona, the best beer made in the world!" The bartender grabs a bottle, wipes off the dust and gives it to the Mexican.
The American says "Give me a Budweiser, the most popular beer in the world!" The bartender roots around a bit and then finally finds one and gives it to the Yank.
The Irishman says "Give me a Coke." The bartrender looks at him and says "Don't you want a beer?" The Irishman man replies "If me friends here won't be drinking a beer, then no Guinness for me either!"
Friend of my soul, this goblet sip 'twill chase the pensive tear. 'Tis not so sweet as woman's lip but oh, 'tis more sincere.
Clan Mac Cullaich: - Brewed in Scotland - Bottled in Ulster - Uncorked in America