By chance, Lingmi returned to the summer of 2016. She didn't know whether she was happy or worried for a moment. She was happy that she could make up for the regrets she had discovered after growing up and spend her precious three years of high school life again. What she was worried about was that her future would still be unsatisfactory, and would this opportunity to come back suddenly end, or would time continue to pass according to her own wishes? What kind of changes would there be?
Concept: A regretful life means that you obviously have a lot of time to waste, but you are always able to make the most correct choice, or the least wasteful choice, at the critical moment.