I do not fully understand the process of understanding of a material one reads. Suppose someone reads a chapter from a physics book. How does one make sure that one has really understood what she/he had read? I must confess that at times I read from text and I even feel that I had understood the content but later (may be at the time of exams or solving assigments or when somebody raises a question from that topic), I realize that the feeling was illusory and I feel so stupid. At times I feel that my understanding is incomplete even at basic levels. I am eager to know from experienced people in this forum if there is any method to test whether one has really understood the content of what one had read. I am talking of advanced level physics courses. Thanks.