An excerpt from the Psychology Today Blog:

Over the next month I want you to develop the habit of confronting fear. It’s my opinion that the human body needs fear. You may not have noticed, but on the government’s chart of recommended daily allowance of essential vitamins and minerals, just under Vitamin E and above Folic acid, is Vitamin F for fear. A healthy person has a bit of fear in their lives every day. Without fear, you’re not challenging yourself and growing. You have your choice—I’m prescribing ten minutes of apprehension or two minutes of utter terror, every day.