Knowing which berries were poison, which cloud pattern indicated a storm, or which bird song meant danger: this kept them alive. On the other hand it wasn't helpful to remember which trees were prettiest in the fall. The most beautiful sunset they ever saw? Well that wasn't going to keep them alive either. Over time nature rewarded the worry-warts and we've been living that legacy ever since.
So it's not your fault, you see.
You're biologically programmed to fear.