The Yoga Sutra gives us an invaluable map of the mind. The mind is like a lake. The Purusha or Self, is the lake bottom and the lake itself is the chitta, mind-stuff, composed of manas, recording faculty; buddhi, discerning faculty; and ahamkara, egoism.
Like a cauldron of water, the chitta is colourless, odourless, and without shape; but it takes on the form of thoughts and perceptions and other activities that arise within it. Any sense perception, thought, emotion, or memory arises as a vritti, thought wave; literally, ‘whirlpool’, in our chitta.
And hundreds of such vrittis, or movements, occur within our chitta during the waking state. They stir its surface waters, muddy it, and send out ripples that are electrically charged, which refract and reflect the non-Self and conceal the lake bottom, which is the Self. And these vrittis are stored in a subtle form in the chitta as memory.
The yoga science of mind clearly demonstrates how any thought process creates an opportunity or tendency, for us to repeat it. This tendency is called a samskara. Samskaras form habits, which create an individual’s character.
For example, if someone insults us we naturally become angry. From the yoga perspective, that reaction is like a pebble, as it were, dropped into the lake of our mind, the chitta. And each time we remember that insult, its memory reawakens our anger and another pebble is dropped into the lake. If we remember such an incident thirty times a day over twenty-five years’ time, imagine the pebble deposit; it becomes a huge pebble embankment!
Source – Prabuddha Bharata – January 2019 page 82 – article titled Yoga’s Gifts to the Contemporary Western World Pravrajika Brahmaprana.