The nature of reality is dictated by the amount of mental energy directed toward given thoughts/concepts.
It has been said that we attract what we fear.
While this often appears true, were it so, there would be many more snakes it our cities.
The content of reality is dictated by the sum of mental energy we place into concepts - whether they be fear or love inspired.
We appear to attract our fears because our worrying/concern/thinking about them infuses them with the energy necessary for manifestation. The excessive manifestation of fears is caused by our preoccupation with them. Consider 9/11...