The act of memory / remembering is the non-escaping of the experienced objects
Rishi Patanjali describes memory as the non-escaping (i.e. retention) of past experiences in the mind. The process of memory starts first as an impression in the mind and becomes active when mental images are formed. It is then that it becomes a Citta-Vrtti or modification of the mind. It is through memory that we build associations. In order to not become attached to past experiences or distorting memories through fantasies, one must practice witnessing the process of remembering while bringing the mind back to the here and now.