While my time in Ireland has actually left me with a greater personal devotion to Colum Cille/Columba, I'm still nevertheless more than mightily impressed with what Patrick accomplished, even sifting out the later legendary material as best as we can. If you ever get a chance, read his Confession. Hell, look it up now online! Granted, it's difficult. The English looks messy. The Latin is worse! And he assumes too much for our understanding, certainly never foreseeing people trying to puzzle out his references more than a millennium-and-a-half later, but still it is a powerful testament to a man of unusual spiritual vision. Before him, Ireland had resisted Christianity almost uniformly. Within 25 years of his life, the entire island is more-or-less Christian, with the Druids converting in droves as Patrick makes the graceful move of converting their culture as well as their persons, seeing that Christianity was in fact the perfect answer to the questions posed by druidism. (Much to the chagrin of the would-be druids of current neo-paganism.) Like Francis of Assisi, we've sentimentalized Patrick in order to tame him, to avoid the real challenges posed to us by consideration of such persons as the saints. But damn if the reality isn't astonishing.
Happy St. Patrick's Day to you.