Don't waste time in answering to this question. Give a prompt and straightforward answer. For example, you can say that I am always confident and till date I have seldom gone wrong during my entire career. Please note that with this answer you might be cross questioned many times but believe me that your chances of being selected is maximum if you are prompt. With this answer I really want you to understand that you should be quick in answering any question. Do not allow the recruiter to think otherwise you will definitely be in problem.