When I attend to lectures I can gasp the ideas very quickly. When lecturer explaining something I can even think what is he going to teach next. Actually, in the class, I am faster than the student who gets the highest grades for exams.
But the problem is when I am facing exams I always get low grades and it is hard to face the exams.
Can someone give me any advice to overcome this situation? Thanks in advance.
You don't practice enough. You need to take the problem,
which you think that you know perfect and try to write a full solution.
I am sure that you'll see troubles.
Good luck!