The fear is simply you're not living with life, you're living within your mind.
Such an inspirational snippet with Sadhguru , Eckhart Tolle and Mooji. If you've got five minutes have a look.
This really resonated. The idea of fearing something that hasn't actually happened yet, so, therefore your fear is about something that does not exist.
I was caught off guard by a bad dream the other night. I find these days that most feelings I encounter when I'm awake, I'm able to sit with. Acknowledge the feeling (not always comfortable!) before any thought is attached to it, which would give it momentum to become a fear that I believe in.
However, this dream was potent and then lingered around. It started invading my thoughts, to the point I was quite freaked out and thought I'd be faced with the monster as I ventured into another room!
So, it's been another lesson in becoming an observer of thought and feeling without being totally consumed to the point they become a reality. AKA Insanity! ha!