This caught me kinda off guard.
Had to think long and hard and found out that I was "prepping" before it was called "prepping" and before any thought or concept of SHTF probably existed.
I have to attribute my "prepping" mindset due to spending so much time with my beloved Grand Mother, God rest her soul.

She went through the depression so never took ANYTHING for granted.
Not her friends and neighbors, her faith and family, her garden or the simple plastic bag that bread came in.
(She usually baked our own bread but I think she would buy a loaf just for the bag.

)
e.g. When the bread bag was empty, it was washed and hung on a hanger with clothespins to dry by the heater vent and then used to carry my lunch in.
After my lunch, lunch's waste like paper from sandwich wrap, aluminum foil that covered my frozen soda to keep it cold till lunch, the soda can, paper napkin and any wrapper from amenity's all came home in the bread bag.
Upon returning home, can was crushed and separated along with AL foil, paper products placed in burn barrel and bread bag again washed and hung on a hanger with clothespins to dry by the heater vent.
Nothing was ever wasted, things were always "prepared" and ready for use so I guess it was never about when SHTF, it's like living as if it already had !