In the beginning, it’s easier to experience our controlling mind, with all our attachments, than the open mind of doubt and unknowing. So the exercise is first to make a list of all our attachments. These might include ideas or things. You might, for example, list possessions you think you need, such as a certain kind of car or clothes. Then you might list ideas you consider important or true, such as the belief that you need to eat meat to get enough protein. The point is to lay bare all our attachments—everything we think is essential to who we are. Only when we let go of these attachments can we experience the open mind of doubt.
From Instructions to the Cook: A Zen Master's Lessons in Living a Life That Matters by Bernie Glassman and Rick Fields, page 52.