Memory retrieval is thought to involve reengagement of neural populations that were active during the actual experience. However, memory processing in our brain is completely different than simply replaying the stored information in computers and involves much more dynamic information processing. In the first part, I will focus on retrieval-induced processing beyond reinstatement of memory. Our findings suggest that retrieval signal itself can trigger changes of memory traces such as memory strengthening in the hippocampus. We demonstrate a retrieval-induced strengthening process of associative memory trace in CA3/DG, leading to the long-lasting maintenance of memory. In the second part, I will present the study of the neural basis underlying the confidence of our false memories that were never stored in the brain but are assumed to be experienced. Taken together, these results suggest that our memory traces are dynamically reorganized in the brain to efficiently guide and support our behaviors.