Worry is one of these bad habits which, once established, are very hard to break. A curious feature of this habit is that, in certain cases, though you may remove the cause for worry, and the subject may admit that the cause has been removed, the removal of the cause does not remove the “mental” state which the subject declared was the cause of the worry. The fact is, the person has developed the worry habit, a state in which he manufactures the stimulus to worry.
FM Alexander (“Constructive Conscious Control of the Individual” – footnote p139)