Insight: The act of grasping the hidden nature of things.
Worry: The act of feeling persistently uneasy about things

“Most people believe that worry is a conscientious state of mind. As a result, they mistake their worries for insights. They have a thought about upcoming events, the thought produces an uneasy feeling, and they assume (because of the uneasy feeling) that the thought has merit and needs consideration. In my experience, however, the opposite is true: An uneasy feeling—a worry—is a sign that one’s guess about upcoming events has no merit and needs no consideration. And if a person thinks it does, his or her peace of mind and performance level will decline.

Worries build when we ponder the future from an insecure mind-set.

All people possess the capacity for both worry and insight. People worry when, from a low state of mind, they make assumptions about the future and imagine what will happen if these assumptions prove accurate. Insights, on the other hand, do predict the future. Insights are the opposite of assumptions and, since they are the byproduct of an elevated level of consciousness, they feel free and uncomplicated.

Insights are responsible for all of your productive decisions and actions.”

Garret Kramer in Insight, Worry, and Why You Need to Know the Difference