"I was surprised his nose was not growing like Pinocchio's." This refers to the story of Pinocchio, where his nose grew whenever he told a lie. It is from The Adventures of Pinocchio, written by Carlo Collodi.
"When she lost her job, she acted like a Scrooge, and refused to buy anything that wasn't necessary." Scrooge was an extremely stingy character from Charles Dickens', A Christmas Carol.
"I thought the software would be useful, but it was a Trojan Horse." This refers to the horse that the Greeks built that contained all the soldiers. It was given as a gift to the enemy during the Trojan War and, once inside the enemy's walls, the soldiers broke out. By using trickery, the Greeks won the war.
"He was a real Romeo with the ladies." Romeo was a character in Shakespeare's play, Romeo and Juliet, and was very romantic in expressing his love for Juliet.
"Chocolate was her Achilles' heel." This means that her weakness was her love of chocolate. Achilles is a character in Greek mythology who was invincible. His mother dipped him in magical water when he was a baby, and she held him by the heel. The magic protected him all over, except for his heel.
