What was your worst experience with a customer at your last serving job?

Giggle, and share that one awful experience by starting with a high-level overview of what happened. The interviewer is most interested in how you respond to the situation, so be sure to mention that you did not allow the situation to get the best of you and maintained a positive attitude. If you needed to apologize to a customer for the situation, be sure to mention how you sincerely apologized and how thankful the customer was for the apology.