The “Better in Boston” magnet comes to signify Lily and Atlas’s whole notion of the future, one where they are happy and successful and, most importantly, together. By never getting rid of the magnet, adult Lily never fully lets go of the hope it symbolizes—even after she falls in love with another man. Regardless of what the teenagers hoped would happen or what does happen in the future, they agreed that loving each other changed both of them irrevocably.