Theme: People should follow their hearts, even if told differently Act 1, Scene 5
Act 2, Scene 1
Act 5, Scene 3
Romeo is speaking to the "dead" Juliet. He has snuck into the tomb to see her dead body, he loves her and wants to see her.
Act 2, Scene 5
Romeo has followed his heart into marrying Juliet. It is a secret from their parents. So even though their parents would disagree, they followed their hearts.