The biggest threat is our dependence on digital technology.
Not many can read a map anymore and they reply on GPS etc
One day our power will shut off from overuse or deliberately and its results would be chaos.
Learn to use old methods like a compass,map,instructions to operate machinery by hand etc
Other than an old fashioned bike many will have serious transport problems.
Refrigerators will shut down as well as microwaves etc
One should learn how to store food on how to dehydrate foods and make preserves etc
How to filter water from a stream etc.
These will come in handy should a disaster strike.