Enlightenment of illusion

"Does anyone here believes in superstitions?" the professor of phycology asked his fresh batch of students on their first day at med school. Everyone denied as they thought being a science student they shouldn't believe in myths and even if they did, the professor didn't need to know that. They had made up their mind that he wanted to hear a denial as response but he didn't seemed content with their reply. "I'm asking again...Does anyone here know that they are subconsciously!" he rephrased his question. 

Although it did made the students think for a second but they again replied in denial. Professor smirked and then rested his arms on the table. "If that's the case then I want you all to take a piece of paper and write 'I'll lose both of my parents today' on it." he commanded. Nobody could gather the courage to write a word. "So today you all learnt a little about yourself." he said as he left the class.