Realy nice story. I loved reading it.

Besides the touching ending, I really like how you describe the problem of missing confirmation for teachers that their work helped. It's a serious problem for education in general because of the long-term goals of education: the success of the students in their lives. But the feedback for the education system stay out or is too late.
I hope that this will improve in the future because feedback is key to improve yourself and this is true for the educational system as well.

Your story made me think about my own teachers in high school. I think I will have to send 'Thank you' emails to some of them (I just started studying so it's not that long ago, but still, it might help them to stay the good teachers I had in high school).