Password/key(s) you don't have to remember even if home burns to the ground.

The only item you'll need is a book of which you can keep on hand but don't worry if your home burns down preventing you from retrieving any private key, for the book can be sourced again as long as a first edition of some popular book was utilized.

Turn to any page number that you should be able to remember. In my case, page 60 since I was born in 1960. Select and remember a page number that's best for you.

Extract the first letter of every third(?) word till you have 31(?) characters. If you start with the first word, that letter would be automatically capitalized. In kind, if you happened to stumble upon another word that begins a sentence, retain its capital as well. Convert at least one letter to a number, i.e., the letter "i" to the the number "1" and/or the letter "o" to "0".

SthalacectasncOcffssHd1bfbhtL1j

For illustration purposes, I grabbed a book of the shelf that I'm highly fond of and extracted the above password/key using the process I laid out. Now, if I were to lose that book, I simply source another copy, turn to page 60, and extract what's needed.

Note, I used "third word" and "31 character" because I'm fond of pi.

Are there any flaws to this practice? Can it be modified for simplicity or security?