You know when you feel like there's something you're forgetting but you can't quite figure out what it is?
Well, someone in Cork obviously realised what it was they had forgotten.
Two library books were left in to Mallow Library, one of which was due back on 21 March 1972.
The person responsible put the books in a plastic bag marked 'Cork Council Library' in a letterbox and the postman left them with the library.
Speaking to Patricia Messinger on C103’s Cork Today Show, library
manager Liz Desmond said staff "love a bit of mystery to brighten up our
It seems that whoever left in the books was obviously worried about the payment.
Desmond couldn't say how much the fine would have been worth, as there were currency changes to take into account.
However, she said that they wouldn't fine someone after that amount of time, and they were just excited to get the books back.
You can hear the full interview below: