to make someone remember an unpleasant event or situation that happened in the past.
For many soldiers who served in Vietnam, the current conflict has reopened old wounds.
reopen old wounds
To bring up or remind someone of a painful, tragic, or unfortunate past event or situation. Seeing Jessica with her new girlfriend reopened a lot of old wounds this afternoon.The fight got pretty nasty, and we both started reopening old wounds from years ago.
reopen old ˈwounds
remind somebody of something unpleasant that happened or existed in the past: Look, let’s try not to reopen any old wounds this time, OK?