"Then I felt something missing, and I was unhappy. When I was about to graduate, I was struggling between two choices, whether to continue as a volunteer teacher or to continue my education," she recalls.

She thought of her beloved grandmother, who had brought her up, and the days when she would sit on her lap under a big pagoda tree in the yard.

"Grandma pointed at the ants on the ground and told me: 'The ants will die when we stamp on them accidentally. Pigs, horses, cows or sheep cannot control their fate, either, but we humans can. You're endowed with such great power, so you should not only create a good life just for yourself, but also for others'," Kang recalls. "I've always followed her guidance, so I decided to give being a volunteer teacher another go."

When she was preparing for her overseas studies, she received a box of letters on Sept 10, 2017－Teachers' Day－from her students, who had continued leaving their poems in her dormitory even after she left. Then a poem changed her life.

It was by a girl called Xiao Linghua, 13, who also wrote a letter to her, in which she confided a secret: "Miss Kang, do you know that I'm not fatherless? But my father is in prison, so my mom supports us three girls on her own. When other people said that I was a fatherless child, I never fought back. However, I fought back for the first time in my life when my poem won the second prize, but some claimed that I must have plagiarized it. I said that I wrote it myself, and it was recognized by a real poet, Wang Jiaxin."

With the letter, Linghua also sent Kang a new poem of hers: "People in Heaven light the stars/People on the ground pray." Following the line of verse, the girl wrote: "I hope more children can find themselves through poetry like I did."

Kang says: "At that moment, it occurred to me that it's not that the kids can't leave me, but that I can't leave them. I want to do more."