It is all about your preparation strategy. Some do it in group and some look at coaching institute for help. Understand the basic purpose of 'Mock Interviews'. Gain confidence, not how to act in front of Interview Board.
It is absolutely fine if you want to evaluate your preparation and want to ascertain how people rate you.
No harm in reaching out to experts, seniors, successful candidates who can guide you to sail through the Personality Test.
Learn to be composed and make use of these mock interviews to build confidence and remain relaxed during the interview.
People share their own experiences or may be what other candidates faced during interview earlier and how they were rewarded for that particular performance.
But, you need to be extremely cautious that your answers do not sound like rehearsed. Every individual is different and have different background and even circumstances.
So, don’t try to mimic what others suggest. Relate the situations with your conditions and smartly adept the things which match you.