What does the passage focus on?

Most people think taste buds in the mouth are the reason eating and drinking are a pleasurable (or sometimes repugnant) experience. However, these tiny bundles of nerves are responsible for only part of the show. Taste buds provide just a single-note experience of what we consume.

Dinah Sykes, a parent of two boys in a suburb of Kansas City, started noticing changes to her children’s public schools a few years ago. Class sizes were growing. The school library had stopped buying books. So she used her position as the president of the parent-teacher association to start a new tradition: instead of bringing cupcakes to class for their birthdays, students were asked to bring a book to donate to the school library.