After reading this thread and buying a few things. Rethinking a few things. ... and just having so many 'things' that I don;t use that often or hardly at all.

The most unusual thing I am going to add is an instructional manual that is written in my words with large type and photos. Waterproof storage on paper and pdf.

Why large type.... all of the manuals seem to like microscopic type these days and if I were to lose my contacts or glasses they are useless to me.
Why pictures... same thing.... I may not have time to recall 'what goes where'.
Why not just re-write the manual?... Because I want it in my words. After learning the 5 step manual way. I want the two step real world way.

There are so many things we use that it's near impossible to remember how everything works. What if I remember there is a trick to figuring out what time of day it is, or how to reset a certain device. Well I don't have time to read through a survival book.

So that's going to be my addition. My spare brain that remembers the things I have available to me and how to use them quickly and safely.

I had to go to a forum,that then referenced my owners manual, on how to reset a 'service due' on my 4Runner that took me say an hour to 'remember' a 10 second sequence of pushing buttons. If I had my own survival manual, I could have solved that issue in 2 minutes.

... and the worst part would be if someone else had to use your gear to save you and they had everything they needed but no instructions.

So I have come to believe that everyone's gear bag should have an owner written instruction manual that practically anyone could read quickly and utilize.