all our roles

we learn them as children, often in the 'school of hard knocks'.
g pro·tag·o·nist n.
http://www.answers.com/topic/protagonist
The main character in a drama or other literary work.In ancient Greek drama, the first actor to engage in dialogue with the chorus, in later dramas playing the main character and some minor characters as well.
a. A leading or principal figure.
b. The leader of a cause; a champion
http://en.wikipedia.org/wiki/Protagonist
A protagonist (from the Greek πρωταγωνιστής protagonistes, "one who plays the first part, chief actor"[1]) is the main character (the central or primary personal figure) of a literary, theatrical, cinematic, video game, or musical narrative, around whom the events of the narrative's plot revolve and with whom the audience is intended to share the most empathy. In the theatre of Ancient Greece, three actors played all of the main dramatic roles in a tragedy; the leading role was played by the protagonist, while the other roles were played by deuteragonist and the tritagonistprotagonist can be some who saves some one like a super hero in a book or movie.

the deuteragonist (from Greek: δευτεραγωνιστής, deuteragonistes, second actor) is the second most important good character, after the protagonist and before the tritagonist.[1]DramaBecause Ancient Greek drama involved only three actors (the protagonist, deuteragonist, and tritagonist) plus the chorus, each actor often played several parts. For instance, in Sophocles' Oedipus Rex, the protagonist would be Oedipus, who is on stage in most acts, the deuteragonist would be Jocasta (Oedipus' mother and wife), as well as the Shepherd and Messenger. This would be because Jocasta is certainly a major role—acting opposite Oedipus many times and occupying a central part of the story—and because the Shepherd and Messenger are onstage when Jocasta is offstage.[4]