Our tendencies or habits (vasanas)to react in the form of thought, speech and action is rooted in the grooves (samskaras) that are stored in the subconscious mind (chitta). Samskaras are created when experience happens through organs of senses and action (gnanaindriyas and karmaindriyas). The deeper the experience like intense pleasure or trauma, the deeper the groove. These grooves create tendencies that drives individual to think , speak and act in a certain way and shaping the character. 

Just like the vinyl record of gramophone encode sound vibrations by making grooves on the record, the chitta (sub conscious mind) records the experiences of pleasure and pain as samskaras or mental grooves. Groove can be of 3 types and can be compared to the following: 

• Drawing a line on water
• Drawing a line on sand
• Drawing/chiseling a line on rock 

For example, attachment to intense pleasure or aversion to intense pain is similar to chiseling line on a rock. These samskaras influence future behaviors, perceptions and even rebirth and can take lifetimes to be dissolved. 

These negative mental states or kleshas (ignorance, attachment, aversion, ego identification and clinging to life) creates samskaras that are carried across lifetimes. 

Eradication of Kleshas purifies the subconscious mind (chitta shuddi)