Sounds like defragmentation are first sight. Seems likely that the storage algorithm for human memory could use periodic optimization, especially since we recontextualize memories over time.

For example, let’s say we smell a lychee for the first time in a shop, and the brain stores that memory using a given set of neurons. Later, a hawker starts selling lychees in the local train in Mumbai we commute on everyday. Now memories of the smell of lychees and the smells and experiences of Mumbai local trains become strongly linked. At that point, in a simplified model of the brain, I can imagine why the brain may want to move those memories so they are using neurons that are closer together. Defragmentation!

I am likely terribly wrong, but would love to learn in what way I am wrong :)