LitCharts assigns a color and icon to each theme in The Sun is Also a Star, which you can use to track the themes throughout the work.
Immigration and the American Dream
Passion vs. Reason
Interconnectedness and Destiny
Isolation vs. Connection
Summary
Analysis
Natasha agrees to take Daniel to her apartment. As they walk, Daniel thinks of a headline in which he thwarts the US immigration system and stops Natasha from getting on a plane, but he knows it won't happen that way. He wonders if he and Natasha were meant to be, but only for one day.
As Daniel expands his definition of what "meant to be" can mean, it shows that he's taking some of Natasha's beliefs to heart and adding firsthand evidence to his understanding of the situation and the world.