You’re Stranded on a Desert Island (not dessert)

I feel like not enough of you have invested in your primitive survival skills as a hedge against apocalypses.
I think anyone on a desert island is already ahead of the game in regards to primitive survival skills as a hedge against apocalypses. The only thing that they would need to overcome is their own environment (food, water, shelter). In an apocalypse you have to overcome their own environment plus their neighbors. Change the desert island to a neighborhood and 9/10 Dentists would pick the rifle.