Final answer:
Anchises changes his mind about not wanting to leave Troy after reflecting on the rise and fall of cities, nations, and empires.
Step-by-step explanation:
Anchises changes his mind about not wanting to leave Troy because he reflects on the rise and fall of cities, nations, and empires. After witnessing the destruction of Troy, he realizes the changeability of human fortune and acknowledges that it's time to leave. This change of heart is portrayed when he laments the fate of the enemy and sheds tears, indicating his acceptance of the situation.