I disagree. The nature is to EXPECT the very worst to happen. The simple truth is we don't have the power to stop bad things from happening. Its our OCD that convinces us we do. It simply is not possible to prepare for everything. For example, how do you prepare for a natural disaster, a car accident or a plane crash? How do you prepare for a devastating diagnosis like cancer? There are precautions we can take such as a searltbelt, but there are a lot of things in life that are simply out of our control. No matter how much OCD tries to convince you otherwise.
I was unclear. I meant that we feel like we always need to be prepared for the worst, and to try and stop the worst; because our minds are, just like you said, expecting the very worst to happen. Always.