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
Earlier in the day, Jeremy Fitzgerald was hit by a distraught insurance agent driving a white BMW. The experience was just enough to make him consider his life and admit his mortality—as well as the fact that he's in love with his paralegal, Hannah Winter. Later today, he'll return to the office, take Hannah in his arms, and wonder what it'll cost to love her.
The fact that Daniel Christainsen (the man who almost hit Natasha earlier that day) hit Attorney Fitzgerald reinforces the idea that all people are connected in myriad ways that might seem mysterious.