To do this, you must go beyond your self-identity as a student. To write a dissertation, you must see yourself as an expert, who is ready to claim your rightful place among the other experts and authorities in your field.
For most of us, our educational experiences don't prepare us to make this psychological shift. How often did anyone regard you as an expert on anything in your student years?
In fact, our educational process taught us just the opposite. We were taught to learn the "right answers." The experts defined the right answers, and judged our exams, essays, and papers, to determine if we had learned the "right" answers.
It is entirely possible that you can reach the point of writing a dissertation without ever writing an original word about anything in your field of study. Teachers tend not to shower good grades upon original thinkers. Good grades are most often given to those who supply the predetermined "right" answers.
Throughout this whole typical educational process, based on learning the right answers, we learned to write essays and term papers. Most of us were never taught how to write a thesis. If your education was typical, you learned how to demonstrate that you had learned your lessons. You learned how to write essays and term papers. You didn't learn to how to declare an original thesis.
The typical term paper usually consists of gathering information on a topic. Your goal is not to provide original information, but to organize existing information provided by experts in your field.
What about essays? You can express your opinions on a topic in an essay, but an opinion is not the same as a thesis.
What most people find so difficult about writing a thesis is that the writer must make an original contribution to the field. After going through high school and colleges, writing term papers and essays, it is an entirely new experience to write a thesis, arguing for an original point of view. But this is exactly what you must to do write a thesis.
When you reach the point of writing a dissertation, you are suddenly the one who is supposed to ask new questions and provide new answers. You must become one of the experts in your field, not simply a student. This is a whole new life experience.
This is the real secret of success behind a successful dissertation. Your success is no longer measured by your ability to learn the right answers. Your success comes from your ability to ask new questions and provide new answers as an expert.
It doesn't matter if your thesis becomes a landmark dissertation in your field. It doesn't matter if your thesis is just a baby step forward. The critical issue is that you must claim that you are an expert in your field, by offering an original perspective. If you don't offer any original answers, you are not writing a thesis.
So, what is the psychological secret behind a successful dissertation? You are claiming to the world that you are no longer simply a student. You are now an expert in your field.