As I said, this is a very vague and uninformed question, and I figured the literature forum is the best place to ask it. So I seem to remember a (an Irish?) folktale of some sort, about a boy who went out walking and a storm came. He found a cave, where some elves (trolls?) lived and they invited him to dance with them before he went home. The boy agreed, and he danced with the elves all the jolly night long and when he left the cave the next morning, he saw that he had been missed for 1,000 years.
I realize this is a very generic fairy tale, and I was thinking maybe the Grimms wrote one about it...? At first, I thought it was "Rip Van Winkle" but then I looked it up and that wasn't the story at all.
Anyways, I've been scouring wikipedia for about an hour now and can't find much. Maybe I'm not searching right...? Help?