Many students in India, where around 650 million people still lack toilets, can’t say the same. Most schools I visited had filthy latrines, used only because there was no alternative. Some had none at all. Students and teachers made do with fields and back alleys.

Concentrating on lessons when you are desperate for the bathroom is hard on anyone. It’s nearly impossible for a girl who is menstruating and has nowhere to change or dispose of her pad. Girls grow tired of dealing with it. Often their families encourage them to stay home from school and get married. In one survey, 23 percent of Indian school-age girls dropped out of school when they reached puberty.

“Girls suffer if they aren’t empowered to manage their menstrual cycle without pain and shame each month,” said Chris Williams, the executive director of the Water Supply and Sanitation Collaborative Council, which runs the Menstrual Hygiene Management Lab. “Their health, schooling and dignity are in the balance.” And the world suffers, too: educated women are healthier, have smaller families, often earn more and have a positive impact on development.

It can take years, even generations, to change a taboo. But anecdotally, outreach workers note that the only girls who don’t believe the superstitions about menstruation are those with educated mothers. So the best way to change the minds of future women is to keep girls in school today, and basic lavatory facilities are one of the easiest ways to do that.

Back in Ankita’s schoolyard, something revolutionary was happening. Although many male teachers in rural India are terrified that broaching the subject of menstruation will be considered inappropriate or worse, one of Ankita’s teachers was different. After attending a Yatra outreach session, he used 200 rupees (less than $4) of his own money to turn a disused latrine into a simple incinerator, which girls could use to burn their dirty cloths.

It isn’t perfect: girls still face the embarrassment of going to the incinerator with everyone knowing why. But this rudimentary construction, with its vent made from a discarded well-water pump, could have huge consequences. Not only could it bring educational salvation to Ankita and her classmates, but a better future for generations to come.