Compare Romeo's behavior before he meets Juliet with his behavior after they declare their love for each other. What do you learn about Romeo from the change in his behavior?

Before meeting her, he was moody and gloomy, because he had been rejected by Rosalie. After meeting Juliet, he insists that he could find no greater love than she, and wants nothing more than to see her always. It can be inferred that based on his behavior, he doesn't know that love really is, and that he's extremely rash in his decisions.