No sir, you don't understand, I'm really dumb!

Hector and I were working with a neat teenage group, self named Youth Education Tekies. These mostly high-schoolers, living in some of the poorest colonias (unicorporated communities) of the lower Rio Grande Valley of south Texas, had taken upon themselves the task of setting up and maintaining a computer lab in a community center that is not much more than a wood-frame house typical of those in the neighborhood.
Evenings, adults and older relatives would congregate to learn how to use the computers. Many of the adults were minimally literate in Spanish and with no keyboarding skills. M. a highschool junior 'tekie' was a wonderful tutor and mentor with the adults. M. was skilled and proficient in using the computer, surfing the net, and finding appropriate sites. She was also pacient and sensitive as she coached and guided the adults just barely learning to find the letters on the keyboard. One lady, call her Doña Chencha, was elated because she was able to type her name. M. helped her put it it in a Power Point frame, with a fancy font and in very large type. Both Hector and I lauded M. She kept ignoring our very specific praises. "You are such a good teacher." "You are so proficient on the computer" "You are very pacient and don't mind repeating instructions to the ladies you are guiding".
She would keep contradicting us and claiming lack of intelligence. She reminded us that she was repeating Junior year and flunking was a pattern that went back many years.
"But we see you as brilliant" and we would proceed to enumerate all the specific instances, seen by us and others, of her intelligence.
She finally confronted both of us.

No sir, you don't understand. I'm really dumb. You say those things because you like me, but I am very bad in school. I'm probably not going to finish high school.

To me, these were obviously old recordings. Someone, someones, had consistently and persistently told her she couldn't learn. Who had taken so much time and effort to say these things with such persistence? Could it have been teachers? Loved ones?
Who can say that words didn't hurt M.?