Board Thread:Questions and Answers/@comment-40236192-20190808153514/@comment-26907577-20190811180116

Not of the pacifist route; of befriending her. Resetting after True Pacifist wipes all memories (including Flowey's) and deja vu (Toriel knowing your pie choice, Undyne knowing you as a friend, etc). Resetting after a neutral (including all branches of neutral-pacifist) doesn't, and causes the faint memories.