Shakespeare shows the complete character of Julius Caesar through Caesar's emotional experiences. Throughout the play, Caesar deals with every emotion ranging from pride and confidence to fear and betrayal. When the play begins, Caesar is portrayed as a god (in his own mind). He is confident and prideful. He believes his life to be perfect. However, as the play continues, we see that Caesar becomes a shell of his former persona revealing that he is human. These are all emotions that every person deals with throughout their lives. By allowing us to see all sides of Caesar, we realize that he is a complete / round character. As the reader, Shakespeare allows us to take part in the play as Caesar's id and ego; thus revealing all aspects of this characters persona: including his flaws.
Remember: All that glitters isn't gold.