Amid the ups and downs of marriage, Yan Lidong and Mu Chenxi find their fates intertwined. Misunderstandings and conflicts push them to the brink of divorce. However, when Yan Lidong is injured while saving Mu Chenxi, he unexpectedly loses his memory, causing his mind revert to that of a 19-year-old. As they navigate this unexpected turn, Mu Chenxi begins to realise the neglect and indifference she once showed. Through her time with her husband, whose heart and memories remain at 19, she gradually rediscovers the power of love and its sweetness.