Neither do I

"Two young engineers applied for a single position at a computer company. They both had the same qualifications. In order to determine which individual to hire, the applicants were asked to take a test by the department manager.
Upon completion of the test, both men had each missed only one of the questions. The manager went to the first applicant and said, ''Thank you for your interest, but we've decided to give the job to the other applicant.''
"And why would you be doing that? We both got nine questions correct," asked the rejected applicant.
"We have based our decision not on the correct answers, but on the question you missed," said the department manager.
"And just how would one incorrect answer be better than the other?" the rejected applicant inquired.
''Simple,'' said the department manager, ''Your fellow applicant put down on question #5, 'I don't know.' You put down, 'Neither do I.'''