I should not celebrate it, given that rumor about him and the snakes, but most likely it is just a rumor:
Pious legend credits Patrick with banishing snakes from the island, though post-glacial Ireland never had snakes;[37] one suggestion is that snakes referred to the serpent symbolism of the Druids of that time and place, as shown for instance on coins minted in Gaul (see Carnutes), or that it could have referred to beliefs such as Pelagianism, symbolized as "serpents".
Then, of course, that other interpretation of "snakes" is what lies in the heart of this here blog, too. Figure it out yerselves, assuming that you are not out drinking green beer.