True. When my house was broken into while I was at university, by far the most valuable things there were mine and my housemates' textbooks (a couple of my housemates had law textbooks worth over £200 each, this was back when £1 = $2 btw). The burglars took all our cash, jewellery, CDs, DVDs and they even did the covering-the-floor-with-cereal thing mentioned in TFA. Amid all that, not one book was even disturbed from its shelf.

While this makes sense to me from the illiterate angle, book safes have been around for ages. it seems unlikely that a burglar wouldn't just throw all the books off the shelf and see if on impact one of them exposed some cash, jewels, etc.

You just have to remember which books you put the money in. Every now and then I open a book that I haven't read in years and there are five 20s pressed between the pages.