By submission your research has to be good. You don’t get to that point by luck or by doing only bad work. But is your thesis perfect? Is it impervious to criticism? Probably not. Your examiners might have some notes for you, or even suggestions for changes.
How would you feel about that?
Are you going to be happy if they tell you, “You should change this…”?
Will you feel alright if someone thinks you’ve made a mistake?
Remember, your examiners suggest corrections to make your thesis better. It’s not about you. It’s about the work.