Parasomnia is a word used to describe unusual or erratic behaviour while sleeping. In 1937, the Irish Folklore Commission recorded a fascinating story about St Patrick’s parasomnia from James Reagan (c. 1855-1937) of Tonranny, Gort, Co. Galway. In the story, entitled Naomh Pádhraic a’ Rámhailltigh (St Patrick Rambling), a weary St Patrick tells his servant-boy that he is going to take a nap, and warns the boy to listen carefully to anything he might say while talking in his sleep.
Once asleep, St Patrick begins to ramble and says: “Bad luck to Ireland” . The quick-thinking boy deflects the curse by saying: “If it comes may it be on the tops of the rushes”. When the saint repeats the curse, the boy says: “May it be on the highest parts of the white cattle” (meaning the tips of their horns). When Patrick curses Ireland a third time, the boy says: “If it comes may it be on the base of the furze” (gorse or whin bush). And, to this day, all three are withered.
When Patrick awoke, he praised the clever boy for his responses, saying “you are the best boy that ever was in Ireland” .
Source
‘Naomh Pádhraic a’ Rámhailltigh’ , Irish Folklore Commission, Manuscript 354, pp. 294-296