The degree of the absence of thoughts is the measure of your progress towards Self-Realisation. But Self-Realisation itself does not admit of progress; it is ever the same. The Self remains always in realisation.
The obstacles are thoughts. Progress is measured by the degree of removal of the obstacles to understanding that the Self is always realised. So thoughts must be checked by seeking to whom they arise. So you go to their Source, where they do not arise.