By 'rewritten' do you mean refreshed, like learning material with spaced repetition, or some different/deeper concept? Do we 'move' that information to a different cluster of neurons?

I don't know the mechanics! Just the observation that memories recalled many times tend to change more.

It kind of makes sense in that we do not retain the raw information, it's always interpreted, and it needs to be updated to be in line with other things we know.