The mind is impermanent. It appears as waking or dream [duality] and disappears as deep sleep [non-duality]. There must be something continuous to register its appearance and disappearance.
Memory is part of the illusion; it has nothing to do with ultimate truth. Memory belongs to individuality, whereas the ultimate truth is universal. The illusion hides the truth, the true identity pervades everywhere and in everything in illusion.
One has to find out what is at the root of it.
Life seems continuous but it is within the waking and dream. The form, time and space are reality within the mind or duality. Ignorance gives this impression of reality within the duality or mind.
The memory, recollection that creates the illusion of time passing is based on the false self. When the self is formless the question of memory, birth, life, death and the world does not arise. The one which knows the mind [universe] which appears and disappears is apart and formless. Thus all the knowledge based on the false self [ego] within the false experience [mind] is mere illusion on the standpoint of the formless witness of the illusion [mind].