Thanks for a very interesting and though provoking story, Regina. I do, for the most part, agree--we don't have to let our self worth be negatively impacted by others. I think the problem is that when this happens in childhood--by teachers, parents, friends etc.--it can become so deeply engrained that it's difficult to shake off in later life.
I wrote about how childhood asthma and eczema influenced my self image and the difficulties of moving past it to develop strength and confidence as an adult. https://medium.com/the-memoirist/when-a-chronic-health-condition-has-shaped-your-identity-can-you-ever-see-yourself-in-any-other-85b8ec1391e6
The points you make are valuable for adults to incorporate but maybe just as, or even more so, for children to understand.