As I have mentioned before, and will surely mention again, I’ve been keeping track of the books I read for my entire adult life, and my books spreadsheet is dear to me. Each year, I add a new sheet, because I’ve accidentally shifted the columns a few times, and it was rather difficult to piece back together.

When I want to search across all the books I’ve read, I have to select all the sheets first.

Recently, I was perusing data from over the years, to confirm or falsify a hypothesis for an essay. (The fact the essay was never published says all you need to know about how that went.)

I discovered something strange: every year, going back to 2015, the fifth book I read was the same: The Millionaire Next Door.

(I hadn’t particularly enjoyed the book; I found it repetitive, and barely bothered to finish it at all. But it did change my relation to frugality. In fact, the trio of that book, The Psychology of Money, and Mr. Money Mustache’s posts completely transformed my spending and saving habits.)

Obviously something horrid had occurred. I soon guessed what: when all sheets are selected, entering data into a cell enters it into that cell in every sheet. And since I search much more often than I add data, I usually have all sheets selected. When you type or paste, there’s a warning, but it looks the same as the warning when you’re overwriting a single cell: not concerning. What actually happens is ... very concerning. Let me show you:

Fortunately, I had a backup. I tediously manually restored every row that had been overwritten. Except 2024. My backup drive had run out of space, and I deleted my backup from 2024. To this day, I do not know with certainty what was the fifth book I read in 2024, when I read it, or what I thought of it. I just know it wasn’t The Millionaire Next Door.

Then, later, I found another cell that had been overwritten. My review of The Mom Test by Rob Fitzpatrick had been pasted into the review cell for every book in row 21 going back through time: a book by a Buddhist Rinpoche, a book of Sufi poetry, a Spanish easy-reader children’s book, books by Ursula K. Le Guin, Ted Chiang, David James Duncan, Frank Herbert, O’Henry, Truman Capote, James P. Carse...

I put the restoration process on my todo list, but I wasn’t looking forward to it.

Today, I learned good news: not only is it easy to overwrite every sheet in LibreOffice calc by accident, it’s also possible to paste data from every sheet, into every sheet — even if the values in each sheet are different.

I think of it like operating a hole punch on a stack of paper. One little disc will say a, the next b, the third c, and so on. Then you can punch a different stack of paper with the same number of sheets, and swap the pellets. Watch: