Don't fight your battle without your weapons readyGetting nervous and anxious before any crucial and big events of life like competitions, entrance and graduation exams, job interviews, etc is part of human nature. Degree of anxiety and nervousness before an important event in life varies from person to person depending on their mental temperament. Some are highly anxious while some may be slightly anxious.
The side effect of this feeling in many people is sometimes such that they strongly wish for the event to get over soon so that they can get rid of their anxiety and relax. So for them seeing the event through somehow becomes more important than remaining patient and preparing well for the event. Their anxiety often diverts their mind towards the end of that event and they lose focus in preparing well for the event.
For example, when board exams get postponed few students feel happy that they will get more time to prepare and be thorough with the subject while some student even if not well prepared feel that it should not have been postponed as they are anxious to complete it somehow and remove their burden even if they are not able to perform well. The same thing holds true for job interviews and any competitions. Sometimes the degree of anxiety in people is such that even if they have the opportunity to prepare and then take up that even after some days, they still prefer to take it up earlier as they want to get rid of it soon so that their tension is released.
I think this is not the right mindset for any individual. Important events of our life in most cases come once in life and they decide our future career and growth in life and should be taken seriously with minimal nervousness and anxiety. Also focus should not be on waiting for that event to get over but to thoroughly prepare for the event and give your best effort to perform well.
You cannot except to fight a battle without your weapons ready and sharp as it will be a suicide. Similarly going without preparation for important events in life like competitions, exams, job interviews is like fighting a battle without your weapons ready. These events may be one time opportunities in life hence whenever they come they should be taken up only with full preparedness. In case you feel you are not prepared enough and you have an option to postpone the event you should do it rather than taking it up as it is just to complete it and unburden yourself.