There are things that are likely affecting your present capability of putting your best efforts in your exam preparations. Identify and list them out and keeping them in check
Ways of Life
Imagine this: you have a choice to live your life in two ways.
One: you dream big and set big goals. You believe you have the potential to achieve anything you want to achieve in life. And you set out in this direction.
Two: you live your life in a very secured way; no dreams, no goals, no thinking about your highest potential. Simply living your life from day to day without having any aims or ambitions.
Most young people make the first choice. They hope to have a better future and dream of living a better life. They take big steps for achieving their dreams. They work hard at turning their dreams into realities.
Life is not always as smooth as the plans we make and the expectations we set for our near- and distant future. There are things that affect your life in different ways.
Also, there are things that affect your present capability and the daily efforts you put in to carry out your plans and achieve your goals.
If you happen to feel that you are capable of passing your exams and of giving your best efforts into it, but somehow you find yourself lacking in giving your best efforts, that means that there are things that are affecting your present capability of putting your best efforts in your exam preparations.
Strengths & Weaknesses
Another important aspect of living the life of dreams/goals/ambitions is the learning and enlightenment you gain along the way. You get to know yourself better than you have ever known before.
You get to learn what your strengths are, what your weaknesses are, how to use your strengths to take on the opportunities that are available to you, how to keep your weaknesses in check, how to turn them into opportunities, etc. These are all learning and enlightenment that are part of building your career and life.
If you feel that you are not putting in the required efforts or your 100% efforts in your exam preparation, identify and list out the weaknesses that could be holding you back from giving your best. Instead of getting disappointed by your lack of efforts, focus on keeping your list of weaknesses in check, minimizing their effects on you, and going ahead with your exam preparation.