A young married man who had just graduated from Hogwarts, specializing in Potions, got an entry-level job in an Apothecary in Hogsmeade. His task was to collect ingredients for potions, and his first assignment was to collect Lethe River Water for Forgetfulness Potion. The only source of Lethe River Water was the Lethe River in the Greek Underworld, and since Greece was much too far away to get to by broomstick, the owner of the Apothecary gave him enough Muggle money to buy a round-trip airplane ticket, as well as a jar to hold the water.  Upon landing in Athens, he asked the Tourist Bureau for the route to the Underworld and was directed to a hole in the ground in a remote part of the country. He climbed down a ladder to the bottom of the hole and followed a long tunnel until he came to the Styx River. Charon rowed him across the Styx River and told him how to get to the Lethe River, from which all new souls had to drink to forget their Earthly lives. On the way to the Lethe River he noticed how unattractive most of the Underworld was and how unhappy its inhabitants were, but the Lethe River itself was pretty enough, and the Elysian Field on the other side of the river was exceptionally beautiful, as was the young woman near the far bank of the river. Consumed by desire for her, he put down his jar, swam across the river and chatted her up, telling her details about the Land of the Living that she had totally forgotten. She was so grateful to him that she agreed to make love with him. As soon as his excitement had passed, he felt a pang of guilt: he had just committed adultery. He drank some water from the river to forget his sin, and then he said to her, "I've never seen such a beautiful place or such a beautiful woman!  I want to stay here with you forever!"

"Oh no, you won't!" said Hades, who had just Apparated. "The Elysian Field is only for the virtuous, and you just
committed adultery. You will have to stay in a less desirable part of the Underworld." The woman protested that the young man wasn't dead; so Hades had to escort him back to the bank of the Styx River and Charon had to row him back across the river and tell him how to get back to the Land of the Living, which he did. He couldn't remember where he was supposed to go, but he had his passport and his return airplane ticket with him; so, with the help of several people along the way, he made it back to his home. Of course, he couldn't recognize the woman who greeted him when he entered his house, but he figured that she must be his wife, and he managed to conceal his amnesia from her.

The next morning his wife woke him up, telling him not to be late for work.  He didn't remember where he worked; so he asked his wife to accompany him to his place of work.  The owner of the Apothecary was not pleased to see him return empty-handed.  "Where is the Lethe River Water I sent you to get?" demanded the owner with a scowl.  Seeing the look of utter incomprehension on the young man's face, the owner continued.  "Don't you remember?  Okay, I'll give you something to jog your memory."  The owner gave the young man some Memory Potion, which he drank.  All his memories returned to him, including the memory of the sin he had committed.  He confessed to having drunk some of the water from the Lethe River, but of course he made no mention of his motivation for having done so.  "You moron!" screamed the owner.  "I had to exchange fifty Galleons to give you enough Muggle money to get to Greece and now I won't make a Knut of it back from the sale of Forgetfulness Potion.  You can't be trusted to collect ingredients for me.  From now on you will work here as a janitor for much less money."

The young man's wife asked him how he could have been so irresponsible as to drink that water, and when he gave evasive answers, her suspicions were aroused.  As soon as he went to the basement of the Apothecary to clean up a mess there, she bought some Veritaserum and went home.  That evening, she slipped some of it into his butterbeer, and after he had drunk it, she questioned him again and he confessed his sin.  She pretended to forgive him, but as soon as he had left for work the next morning, she packed up some things, left him, filed for divorce and sued him for half his wages in alimony.  Collecting potion ingredients is a risky business!