The biggest lesson I learned is that this exam is not an easy one, and it should be taken seriously. I am a good test taker and have always felt extremely confident in studying for and taking exams. The feeling I had during my PMP was not the same feeling of confidence I've had throughout my life of test taking....the exam is tricky! You can study all the books (I used 3 in addition to the PMBOK) and learn all the facts, and the exam will still be hard, because it requires you to do some real critical thinking. My advice to the future PMP test taker: study as much as you can for an extended period of time before the exam (4-6 weeks at least), sleep well the night before, clear your day for the exam, eat a good breakfast and go into the exam with a clear head. Do this and you will surely earn your PMP as I did! Best of luck!