> "don't use a gadget"

I agree with this but for a different reason than what the author gives.

When you write in a notebook you can see where what you are writing is within the notebook (e.g. ~1/3 of the way through, etc). That seems like a small thing but I think it really helps with anchoring the memory when writing, as well as with referencing it later. And of course you can also add all sorts of tabs and page markers to help even more.

The same is true when reading a book.