It is necessary to complete syllabus

When i was young, i used to leave certain topics while studying for the exam. The reason was that i was not able to understand the topic and i used to think that i will cover up with the rest of the topics that i know. But this backfired once and i was doomed. Since then i do not leave any topic. So when i was weak in Advanced Firewall and Upgrading topics while studying for the CISSP-ISSAP certification exam syllabus, i opted for ISC2 Information Systems Security Architecture Professional Update simulated questions that helped me achieve 890/1000 in the exam.