Characters
Birds fly to the stars – I guess.
— Cosmo Castorini ‧ Moonstruck

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker offers a dreamy claim, that birds head for the stars, then softens it with a shrug. The words have a wistful, offhand quality: a poetic image of flight reaching upward, held loosely by someone unwilling or unable to be sure it's true.
Context reviewed