Poi is a traditional Hawaiian food, essentially a paste of mashed up taro root. The traditionally polite way to eat poi is with the first two fingers. To eat it with only one finger suggests that you are either stingy, or not really appreciative of the food. Eating it with three or more fingers indicates greed.
Nicole learned about eating poi while she lived in Hawaii for some years in her childhood. It was around fourth grade, and she learned it from her classmates at the public school. For Nicole, this particular tradition stuck with her, because even though she is not a native Hawaiian, and she does not identify with the culture, it is still apart of her child hood experience (Nicole moved around a lot, being the child of a naval officer).
Nicoles particular remembrance of this tradition is indicative of the need to learn about and honor the culture you are living in, particularly if it is not your own. The practice itselfthe number of fingers correlating with etiquettesuggests a fairly universal concept. That is, the idea of moderation being a hallmark of civilized ritual eating.