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
Jeremy Fitzgerald lied to Daniel: he couldn't stop Natasha's deportation because he spent the afternoon with Hannah Winter at a hotel. Fitzgerald will think constantly of Daniel over the next week and in a month, he'll begin the process of separating from his wife. He'll keep the promises he makes to Hannah Winter. His children with his first wife will never be happy in love. His children with Hannah will love without complication and without fearing its loss. For Hannah, her story ends with a happy ever after.
The narrator's assessment of how Fitzgerald's children with his first wife will end up versus his children with Hannah shows that one thing people do learn from their parents is how to love, and what love even means. This explains some of Natasha's hesitation at getting involved with Daniel, given that her parents didn’t demonstrate a positive example of love.