David Black, 60, said he borrowed the art book about Spanish painter Goya in September 1962 and it was overdue for 18,417 days, amassing a fine of $4,067 that was dismissed when he returned it to the Edinburgh Fine Art Library during an amnesty week, The Scottish Sun reported Thursday.
"It feels good to have returned it. I can now sleep a little more soundly at night," Black said. "I completely forgot to return it. It would pop up every now and again over the years -- but each time it would slip my mind."
The library said more than 4,000 items were returned during the amnesty period.
"This is a wonderful story and, of course, the Fine Art Library are very happy to have their book back after 50 years," said councilor Richard Lewis, the city's culture and sport convener. "The fines amnesty for National Libraries Day has proven a real success. We've been delighted at how many people have taken the opportunity to come back into their local library."