As John and Tita are spending time together, John wants to show Tita an experiment while his matches are drying. John states, "While phosphorous doesn't combine with oxygen to burn at ordinary temperatures, it does burst into flame very rapidly at an elevated temperature; watch." After he shows her this, he explains his grandmother's theory "that each of us is born with a box of matches inside us but we can't strike them all by ourselves."

John continues to explain that the people and things we love help light our matches; however, the warmth that comes from the matches will eventually fade, and we need to continue to find what will light our next match. If a person don't continue to discover what lights their matches, it will at some point become too late.

This directly correlates to what Tita has just endured. Pedro is what lights her matches, but now that he is gone, Tita is left with no warmth inside her. Hearing about John's experiment and his grandmother's theory helps her realize that it is time to figure out what else will light these matches.

Before John leaves Tita, he asks her to write why she won't talk. Tita writes on the wall, "Because I don't want to." This is very significant because it is Tita's first step toward freedom. For her entire life, she has been controlled by Mama Elena. Now that she is out of Mama Elena's household, it is the first time in Tita's life that she can do what she wants. Her refusal to talk is an assertion of her newfound independence.