Memory and change work together to conjure up the illusion of time. Without one or the other, that could not happen.
Memory is also required to establish a sense of self or identity.
Memory is an awareness of a set of slivers thermodynamically upstream (i.e. in the past) that lead up to the present. That set of slivers that obeys the natural laws that define it. The awareness referred to involves the 'consciousness centre'. The consciousness of each sliver 'recognizes' the other centres in that set. It identifies as them. They identify themselves as one.
The present sliver has a relationship/link/connection to those slivers it recognizes as itself. Furthermore, it senses the degree of separation or the entropic distance that separates them. The greater the separation, the further back in time one's memory seems to reach.