Well, I would think a person could come up with some idea of what would be most likely needed in a survival situation, even before they actually enter into one. The usual suspects come to mind, like keeping warm and dry, or cool and dry, depending on the location and time of year, having something more effective than your voice and/or hand waving to signal possible rescuers with, drinking water would be kinda handy, and maybe something to niblle on once in a while. There are myriad other considerations, but these become more esoteric to the individual, their situation, and what they are willing to put up with.

There's a balance between two different axioms (cliches):

It is better to have it and not need it than to need it and not have it.

Chance favors the prepared mind.(not to be confused with the prepared kit)

Somewhere in between there is the nirvana we all ought to be striving towards.