What if someone constantly thinks about misfortunes happening to them like breaking a leg, losing their house, their car burning down, getting a disease, turning blind, being in a airplane crash, etc.
If they simply think about it(a lot), then it is more likely to happen to them? With negative thoughts they will not put in the effort to make it happen like they would with positive thoughts. If anything, they would put in the effort to prevent the negative thoughts from happening.