"Uncertainty (not knowing what is going to happen) creates more stress than knowing that something bad is definitely going to happen."

Knowing is just easier than not knowing

According to the scientists, our bodies can become so consumed with the stress of “what if” that our adrenaline spikes, our pupils dilate, and our pulse increases. All of those responses occur at rates that are significantly higher than those associated with the actual negative event. 

Maybe it’s a byproduct of our overactive imaginations. One example that comes to mind is Dorothy in the Wizard of Oz. She and her pals wasted a lot of time and energy worrying about a scary confrontation with the terrifying, almighty wizard—who ended up being an old guy behind a curtain. Reality wasn’t nearly as stressful as uncertainty. I think we’ve all had that experience at some point in our lives: Knowing is just easier than not knowing.

Source:

Thrive: Strategies to Turn Uncertainty to Competitive Advantage by Meridith Elliott Powel