There is a piece of foreshadowing in this chapter. What is it? (Hint: it involves Nancy)

In Chapter One, Percy keeps himself from retaliating against Nancy's sandwich throwing in the bus. The following sentence foreshadows that even though Percy kept himself from getting into trouble because of Nancy..... there's trouble ahead.

Looking back on it, I wish I'd decked Nancy Bobofit right then and there. In-school suspension would've been nothing compared to the mess I was about to get myself into.