Meilyr and the Lady
For some time after this Meilyr lost his wits and wandered the land as a deranged vagrant. Eventually he recovered and resumed his former life. But although he seemed to others to be restored to what he had been, he found that he could see things that others could not see and he had the power too see events before they happened. And he saw his lover again, though not as he had seen her before, as she passed through the veil between the worlds and spoke to him so that he found, in repeating her words, that his speech was inspired. So he became a great poet, and a seer, and gained a reputation as a wise man, and a possessor of cunning arts.
All for the love of his lady.
Giraldus Cambrensis told a version of this tale in his twelfth century Journey Through Wales summarized HERE