It is no great secret that my memory has been getting worse since at least 2019.
The other day, I came across an interesting term. A day or so later, I came across an opportunity to use this new word.
Could I remember the word, no.
Worse, I could not remember where I had encountered the word.
It must be in one of the books I read within the last few days.
Eventually, I remembered the word, but still no idea from where.

I have read several books on diverse subjects over the last week. I also may dip into several other books during a day.
Since I have just started reading another of the Mindhack books, I will suggest a “hack” of my own I have now adopted.
On your computer, have a .txt file called “Books Read” (for example).
This file should be easily accessible, such as on your desktop or in the documents folder. It should open quickly, using a program such as Notepad or Xed.
List each book you read and/or complete, in the order you read them.
You can mark books you have started but not got around to finishing.
Also, put down when you dip into a book to find a piece of information or quotation. Perhaps note what it was you found.
Current list looks like:
Information Anxiety
Information Anxiety 2
On Writing Well, Zinsser
Greek and Roman Artillery, Osprey
Steampunk Guide to the Apocalypse
*The I Hate to Housekeep Book" Flagpole memory aid*
Mindhacker–
I do not use a full title and author, just enough to identify the book.
Titles between asterixes are books consulted for references. In this example, I had reread the chapter on memory tricks.
Double dashes are books started but not finished. Depending on your reading habits, there may be several of these.
I suppose I could distinguish between electronic and dead tree books.
A separate column for fiction and non‑fiction is another possibility.
When this list gets longer, I may duplicate the data in a spreadsheet for easier sorting and searching.
I wish I had started this habit years ago. I have folders full of novels where I cannot recall which ones I have read and which I have not.
If you find yourself in a similar situation of being unable to recall where you read something, or even if you have read something, you at least have a shortlist of where something may have been.
Now I just have to remember to keep the list up to date.