When they did Romeo and Juliet in school he was not Romeo; he was Mercutio, dying in lieu of his friend. Months later he was still called ‘a grave man,’ and that just to his face.
Years later, Juliet's rebuke to Romeo after their first kisses still echoes in his mind: ‘Lips that they must use in prayer.’
What people tend to forget is that the age difference in the play is significant. Romeo is a grown man while Juliet is still a girl. Hathaway does not like comparing himself to a teenage girl but, well, it still bloody figures.