Once there was a man named Ulf who had three grown‑up daughters. Each had married a troll and gone to live inside a hill.
Ulf had not seen any of them since their weddings. One day he decided to visit the eldest. He walked till he came to the hill where she lived.
A door in the hillside flew open. “Welcome!” said his daughter, and she let him in.
“Husband, look!” she told the troll. “My father’s here! Will you go buy some meat for the stew?”
“Why buy what is already owned?” said the troll.
He picked up a mallet and hit himself on the back of the head. Thunk! His head flew off into the stew pot, and a new head grew on his shoulders.
“Ah!” said Ulf.
When he got home, he told his wife, “I have learned something wonderful!”
“What have you learned?” she asked.
But Ulf just smiled and said, “I know what I know.”
A few days later, Ulf’s wife told him, “We need meat for the stew. Will you go buy some?”
“Why buy what is already owned?” said Ulf. He picked up a mallet and knocked himself on the back of the head. Thunk!
“Oof!” said Ulf. He fell senseless to the floor.
When he came to, his wife said, “Husband, why in the world did you hit yourself?”
“Never mind!” said Ulf grumpily. “I know what I know!”
Ulf spent the next few days in bed. When the bump on his head had gone down, he decided to visit his middle daughter. He walked till he came to the hill where she lived.
A door in the hill flew open. “Welcome!” said his daughter. “Husband, look! My father’s here! Will you go buy some candles for the table?”
“Why go far for what is near?” said the troll.
He put his hand in the fire. Ssssss. When he pulled it out, his fingers were lit like candles and made the room quite bright.
“Oh!” said Ulf.
When he got home, he said, “I have learned something marvelous!”
“What have you learned?” said his wife.
Ulf smiled. “I know what I know.”
A few days later, his wife said, “We need candles for the table. Will you go buy some?”
“Why go far for what is near?” said Ulf. He stuck his hand in the fire. Ssssss.
“Yeow!” he cried, and hopped about the room, waving his hand in the air. At last he fell in a faint.
When he woke up, his wife said, “Husband, why in the world did you burn yourself?”
“Never mind!” said Ulf. “I know what I know!”
Ulf had to wear a bandage for over a week. When his hand had healed, he decided to visit his youngest daughter. He walked till he came to the hill where she lived.
A door flew open. “Welcome!” said his daughter. “Husband, look! My father’s here! Will you go buy some fish for our dinner?”
“Why fetch what will soon arrive?” said the troll.
They went outside to the well, and the troll jumped in. Splash! Fish after fish came flying out. Then the troll jumped out again.
“Ooh!” said Ulf.
When he got home, he said, “I have learned something wondrous!”
“What have you learned?”
“I know what I know.”
A few days later, his wife said, “We need fish for our dinner. Will you go buy some?”
“Why fetch what will soon arrive?” said Ulf. He brought her outside, then he jumped in the well. Splash!
“Help!” cried Ulf, who couldn’t swim.
His wife quickly lowered the bucket. Ulf grabbed the rope and climbed out, then sat dripping and shivering on the ground.
“Husband, why in the world did you jump in the well?”
“Never mind!” said Ulf. “I know what I know!”
“Well, of course you do, silly! But what do you know?”
Ulf thought about it.
“I know . . . . I know . . . . I know . . . . NOTHING!”
About the Story
The source for this retelling was published as “Pokker med Pengene! Jeg Veed, hvad jeg har Laert!”, in Gamle Danske Minder i Folkemunde, Volume 1, by Svendt Grundtvig, Copenhagen, 1854. It appears in English as “I Know What I Have Learned,” in The Pink Fairy Book, edited by Andrew Lang, Longmans, London, 1897. Grundtvig (1824–1883) was the preeminent folktale collector of Denmark.