In architectural terms, the keystone is a wedge-shaped stone at the crown of an arch that helps keep all of the other stones in place, allowing it to maintain the proper shape. In behavioural terms, a keystone habit is the habit that helps keep all of your other habits in place, allowing you to maintain consistent wellness practices. The keystone habit will differ for each individual. For some, it may be habitual exercise. For others, daily meditation or prayer is essential. It could be a consistent bedtime routine. Whatever your habit, you will experience balanced energy levels, clarity of mind, and reduced stress, which in turn allows you to act in a more purposeful manner in other areas of your life. When life becomes chaotic, focusing on your keystone habit gives you the best chance of maintaining your health and vitality.