As I'm sure we all know here, this test is not easy so it does require some intelligence I guess.. But with that said…
This might sound cliché but I am a firm believer in ‘practice makes perfect'. The more you go over the material eventually you'll pick up enough material to pass the test. It may take longer for some than others but passing is passing no matter how many tries. YOU CAN PASS THIS EXAM!
You need to figure out what is the most efficient way for you to understand, memorize, and rationalize when trying to grasp these concepts. Look for trends and relations in study material, try to relate the material to your personal life, don't over think things, simplify, etc.
What I'm trying to say is find ways to make this easier for yourself. Yes, this is a hard exam but a lot of times we make it harder by trying to over do things. Every person is different and learns differently. A lot of times what helps me is thinking of concepts or problem as if it were me running my own business rather than viewing these concepts as random material I am trying to learn. TRY TO FIND THE EASIEST WAY TO MAKE THIS MATERIAL MEMORABLE FOR YOU. That works for me, it might not work for you but I'm sure there is something that works for you, you just have to find it.
YOU ARE NOT DUMB! The brain is like the body in the sense that if you exercise it will get use to exercise and it will improve and do it more efficiently the more you do it. STICK TO IT AND YOU WILL PERSEVERE!