Because it gets you attention and becomes very catchy. For example I am stuck on band-aid brand cause band-aids stuck on me. lol
Quickly is the correct answer
Think outside the box, and most stories come together better when you come up with a plot first.
Even though Esquivel knows the story of maiz is a myth, she nevertheless warns her daughter not to step on a kernel of corn because the corn represents fertility and the kernels are part of the ritual. It would be wrong, or perhaps even sinful to step on such an important symbol of their culture which is why Esquivel doesn't want her daughter to be in some kind of danger because of such a reckless act.