Ignorance immediately knows things in an ordinary, conceptual way. Because ignorance and its accompanying mental states arise first, wrong beliefs en… - Mahasi Sayadaw

When one cultivates strong concentration by means of tranquility or insight meditation, the mind is no longer distracted by thoughts and other hindrances. Such pure concentration, continuously focused on an object for either tranquility or insight, is considered mental purification. A mind associated with such concentration is also purified of hindrances due to the power of the concentration.

Sometimes the mind may wonder about practice itself. For example, the mind may wander off into analyzing whether an object was noted effectly, or sequentially, or vividly. The mind may wander off into thinking about how one is going to note an object. Under these circumstances, insight concentration cannot arise.

A restless state of mind that wanders away from an object while observing it is a mental state called restlessness (uddhacca). It flies away from the object. Due to restlessness the mind cannot remain very long with an object but often wanders elsewhere.