So how do you not worry about stuff? The problem here I think is, that we human beings are hard-wired to think!
I think that the common consensus is still more or less, that the human brain is divided roughly into two halves, or hemispheres, and one side is for emotional kinds of things and the other logical. Some people have predominate left or right, etc. etc; our great geniuses of the world are thought to be very well connected between the hemispheres. This is perhaps accepted by most people.
I would also throw into the mix Sheldrake’s Morphic Resonance, and you can then begin to see what happens when you start worrying: We are so well connected that big important things always come to the fore, and you can’t so easily forget about them, and put them to one side, because they just fill our heads up. Compartmentalising then? Not so easy?
Well, there are nonetheless some very practical solutions that I think we can all learn quickly and easily. Using stuff that many of us already know: EFT; Buzan; learning techniques… and some mental disorders… etc. etc.