Mathematical "funds of knowledge" (Civil 2007) that students bring from their community and home lives can offer entry points for concepts such as functions and rate of change, which are important "big ideas" across all grade levels (NCTM 2000). The Common Core State Standards (CCSSI 2010) ask high school students to "interpret functions that arise in applications in terms of the context"; "build a function that models a relationship between two quantities"; and "interpret expressions for functions in terms of the situation they model". Making connections to student interests can offer teachers an avenue for introducing key concepts of the Common Core State Standards (CCSS). The authors conducted an experiment in which they personalized problems on linear functions according to students' out-of-school interests in topics such as sports, music, and movies. Research has shown that personalization makes key ideas in algebra more understandable, so that learning persists even when the personalization goes away. But why is personalizing of students' interests so effective, and how can teachers begin to implement this approach in their classrooms? In this article, the authors explore these two questions and reveal ways in which teachers can make connections to students' interests to make algebra ideas stick.