Yes, this is completely true. What is called spiritual enlightenment is basically nothing but the process of knowing all the contents of the subconscious mind, bringing it all to consciousness, until nothing is subconscious anymore. Subconscious mind is the storage of all past traumas, the multitude of illusions and misunderstandings about life, and it’s the source of all human suffering. The suffering that bubbles up to the level of consciousness in daily life is also just the tip of the iceberg of all the suffering that people habitually carry with them wherever they go.