How should you answer 'What do you consider the most difficult situation or experience in your life which you have dealt with' in a job interview?

Dealt with difficult customer?  Difficult experience interview?  How do you resolve a difficult situation?  How did you handle with difficult situation?  What was your most difficult decision in life?  What is the most difficult situation you have faced?  'Tell us about the most difficult situation in your life?  Describe a difficult situation and what you did about it?  What experience did you have with your job that was difficult?  Example of a difficult situation and how you helped to resolve it?  What is the most difficult situation dealt with in the work place?  Situation where you sucessfully applied your skills and experience?  How do you answer 'Tell you about your experience' in a job interview?  Have you ever dealt with a difficult client and how did you resolve it?  What one life experience would you most like to talk about in interview?  Tell you about a time when you felt that you dealt with a situation inadequately and how has that changed how you would approach the same situation?  What was your most difficult work related situation that you have been confronted with and share the situation aspects with us?  What do you consider the most difficult situation or experience in your life which you have dealt with?  How do you answer 'if you have to live your life again what would you change in a job interview?  How do i answer 'canyou give em a example ofwhen you have dealt with a challenging situation'?