Possible Clues:

• Your average Joe
• John Q. Public
• Joe Blogg's morality?
• A late 15th-century morality play
• Tom, Dick or Harry wants poor Mary in uniform
• Mr Average taking famous person aback when so interrupted
• Ordinary person who is not politically correct
• The ordinary or typical person - there's a medieval play about him
• Lines written by graduate in impartial morality play
• Celebrity about to entertain extremely ordinary chap