Romeo particularly expresses self-conflict in act 1, scene 4 of Shakespeare's Romeo and Juliet.
In this scene, Benvolio and Mercutio are trying to persuade Romeo to crash the Capulets' ball with them, both for the sake of having fun at the Capulets' expense and because they know Rosaline will be there and hope Romeo will cheer up if he gets a glimpse of her. However, Romeo at first refuses, saying he feels far too gloomy to attempt to have a merry time.
Yet, despite his initial refusal, by the end of the scene, he has given in to the persuasion of his friends. Though, interestingly, Romeo now expresses that his hesitations are based on more reasons than just the fact that he feels sorrowful. Specifically, he informs his friends that he senses danger in going because he "dreamt a dream" last night (I.iv.52). By the end of the scene, we learn just how seriously he has taken his dream and interpreted it as an omen:
... my mind misgives
Some consequence yet hanging in the stars
Shall bitterly begin his fearful date
With this night's revels and expire the term
Of a despised life closed in my breast
By some vile forfeit of untimely death. (113-17)
In this passage, Romeo is asserting he has interpreted his dream to mean that interaction with the Capulets tonight will lead to his own untimely death.
Romeo's decision to cave in to his friends' persuasion and join them in crashing the ball represents a self-conflict within Romeo because his decision is based on conflicting desires. On the one hand, he rightly fears that going with his friends will lead to fatal consequences. On the other hand, he is young, full of energy, and cannot prevent himself from following in the footsteps of his friends in merry-making, his friends who are "lusty gentlemen" ready to lead the way, just like himself (119). Hence, Romeo's conflict represents a self vs. self conflict because his more rational nature is fighting against his instinctive, emotion-driven nature.