"Heart's fairy tale" or "fairy tale of the heart" could be used to refer to a story or dream that one cherishes in their heart, especially one that is imaginative and fantastical. This phrase does not have a specific origin, but it is a way to describe a personal and emotionally meaningful story that is treasured in one's heart. Here are some examples of how this phrase could be used in sentences:

"Ever since I was a child, the fairy tale of my heart has been the story of a brave knight who saves a princess from a dragon." (我从小就有一个心中的童话，那就是一个勇敢的骑士拯救公主，并战胜了一条龙。)

"The fairy tale of my heart is a story of true love and adventure, where two people from different worlds come together and overcome all obstacles to be together." (我心中的童话是一个关于真爱和冒险的故事，两个来自不同世界的人在一起，克服一切障碍，最终在一起。)

"Even though I'm all grown up now, the fairy tale of my heart is still a story that brings me joy and comfort when I need it." (即使现在我已经长大了，但我心中的童话仍然是一个能够给我带来欢乐和安慰的故事。)