If you do not have a strong object, the mind has more chances to think. If you can be aware of your thinking, then there’s no problem; you won’t be lost. If you’re not skillful and you watch your thoughts, then you can get lost in day-dreaming for a long time.
That’s why you need to use a strong, obvious object, like a physical object. It is easier to use a physical object together with the thoughts to stay more and more with the awareness.
Thoughts are subtle and fast. If you’re not skillful yet, you cannot watch your mind.
Because of physical object, awareness is present; because awareness is present, you can know the thoughts without following them. If you do not have a strong base to keep awareness strong, then it is easy to follow the thoughts because it is the mind’s habit to pay attention to concepts, the storyline. The mind is already interested in the storyline; so, if you pay more attention to the storyline, you get lost.
Now we try to recognize thoughts and come back to the physical object. When you keep doing this, slowly the mind understands that thinking is an object – being known. Because of this understanding, you cannot be involved with the thoughts.