"Realization takes time to steady itself. The Self is certainly within the direct experience of everyone but not in the way people imagine. One can only say that it is as it is. Just as incantations or other devices can prevent fire from burning a man when otherwise it would do so, so vasanas (inherent tendencies impelling one to desire one thing and shun another) can veil the Self when otherwise it would be apparent. Realization takes time to steady itself. Spasmodic Realization is not enough to prevent re-birth, but it can not become permanent as long as there are vasanas." --Sri Ramana Maharshi
In Advaita Vedanta there are two schools: vivarana and bhamati. We can call vivarana the talking school and bhamati the practicing school. The talking school is focused on intensive study of the Upanishads and the practicing school is focused on the removal of vasanas.
Of these two schools, vivarana is the most popular--even in India. This popularity of the talking school underscores something I believe is quite common for any thinking person: the thinking person may easily presume that he or she has not resolved a certain problem or issue, because he or she has not thought well enough about it. Talking gives us food for thinking.
Of course, the main idea with vivarana is that what we think about is to be the Truth revealed through the Sruti and other scriptures. For example, if we think about "Aham Brahmasmi"--"I am the Supreme Reality" then this helps us to realize "I am the Supreme Reality". Yet we can ask, "Is this really how things work? Does thinking about how I already am the Self, help me to realize that I already am the Self? Does thinking make it so? If not, what does?"
If we turn to the bhamati view we find the teaching on vasanas. So we may ask, "What are vasanas?" They are inherent tendencies in our karana sharira or deep sleep body. What we see as human beings are things that manifest within our waking or dreaming states. We can not see the things within our karana sharira because they have not manifested yet. But the bhamati teachings on vasanas say that our inherent tendencies are seeds of good or bad that will manifest into our dreaming and/or waking states if the appropriate conditions arise.
A simple way to understand the karana sharira and our vasanas is to rely on the metaphor of the ground. We all know that the ground is filled with many kinds of seeds. Some of the seeds will grow into fruit-bearing plants, and other seeds will grow into weeds. Everything starts with the seed and once there is a certain kind of seed, then the outcome is simply a matter of time and circumstance. In order to not have weeds grow up from the ground, that ground has to be purged of its bad seeds. It has to be purified.
We many wonder, "How do I transform the vasanas in my karana sharira when they have not yet manifested?"
In the outer world a seed can not be transformed, but in the inner world a seed can be transformed. In the spiritual world our vasanas are transformed from bad to good through practice. Therefore practice is important because practice is what changes the quality of what manifests.
In a transformed life experience it is not only easier for us to live in harmony with others, it is also more probable that we will be able to meditate on and realize the Self.
om tat sat