Possible Clues:

• Unconcerned about what's right, getting minimal mark in a test
• Like a psychopath
• American taking test, not caring if right or wrong
• Having no code of ethics
• Perfume sent back - to many it's not acceptable
• No conscience is needed for a lesson like this
• A maxim that is unprincipled
• Speaking after a number, which is not good at all
• It's commonly wrong in a telegram or a letter
• There's no knowing if it's bad to come at the end of the morning, in a manner of speaking