My biggest prepper mistake was a doozy. Most of my Army career focused on being deployed/assigned to Central and South America, the Deep South or on pacific islands where the environment was tropical.
When I retired after 22 years in the military I had grand plans of using my knowledge of jungle survival. I moved into the bayous of the Mississippi delta about 3.5 hours up the river from New Orleans. Lots of elbow room, lots of tasty things to eat like gators, crawfish, deer, fish.
Then Katrina hit. The populations of New Orleans escaped their SHTF, some permanently, some temporary squatters, some passing through to escape their SHTF.
This event showed me the fallacy of living near a population center. I thought I was tucked away secure in the middle of nowhere deep in the bayous. 3.5 hours up river from New Orleans, even if it’s down good forbidding side roads, isn’t far enough away the crowds. Overnight, all that abundant food suddenly had hungry people wanting to harvest it for a meal. I could go on in some detail how this urban flight from SHTF impacted us and the environment, but I think you all can get this.
We re-evaluated what environmental factors best contribute to isolation from the zombie hoards, and figured we would move to the state with the lowest population density in the US, and among the lowest population density of any country on earth. North to Alaska. The good news was that when we sold our swampland, it was more than double what we paid for it a few years earlier. A lot of folks never moved back to New Orleans, and prices stayed high.
That was my biggest prepping mistake, but I am much better off for it. Plus, most things up here taste great with my cajan seasonings. Good thing as I brought a lifetime supply up to Alaska when we moved.