Interviewing Skills:  Show your competence!

Smart interviewers may adopt a behavior-based interview by asking questions beginning with "Tell me if you have experienced a situation that...", this is for the purpose to determine your past performance, of course it would be more reliable than just let you share your opinion or thoughts.  

Even though the interviewer does not ask, you may provide specific examples of how you acted in the past so as to convince the interviewer about your:

Accomplishments,

Problem-Solving skills,

Can-do attitude...etc..

Therefore, you must prepare relevant and specific stories to make sure that you won't say "I don't know" or "nothing comes to my mind this moment" when you have a chance to show your competence!