When one dwells less on marks, it becomes easy to attain realization.

The tathāgatagarbha itself is a mind that abides nowhere; it does not abide on any dharma in the world, and it itself has no worldly marks whatsoever, let alone the four marks. What needs to break through marks is our mind consciousness—it is the mind consciousness that grasps at marks, it is the mind consciousness that has abiding. Cultivation is to make the mind consciousness reduce its craving and attachment to worldly dharmas, to care less about and dwell less on worldly dharmas. Of course, once the four marks are broken through, it becomes easy to realize the tathāgatagarbha; and realizing the tathāgatagarbha is at the same time breaking through the four marks.