John thought that he could really make a good business by selling those pills. (scene: John imagined that he become rich). He tried to convince the scientist to join him initiating the business.
The scientist felt anxious worried and didn't want to join the business. He tried to stop John from continuing with his idea. John felt something was strange.
John knew that the scientist did something wrong. He forced the scientist to tell the truth. Finally the scientist revealed that the pills he gave was actually empty pills. John felt angry but at the same time he was confused a how the pills actually worked on him. The scientist was also clueless about it.
Siri revealed that the empty pills actually gave John confidence. Previously, the thought of himself being good at everything made him stayed positive and motivated which explained how he got good grades. As john was motivated, he willingly and unconsciously did his revision without feeling burden or stressed out.(He was confident he was going to be good at it).