Well I don't think its supposed to be too easy. However, I'd like to share my experience in the hope that it may add to the wealth of advice already available here.
I am more in the belief that some time submerged in Java in some applied capacity will facilitate a better understanding of Java, its practical application and hence a better approach to the exam. Let me expand;
A few years back I was completely self taught in Java, from books , the Internet and writing copious amounts of code in practice. I took the SCJA after about 9 months and scored high, which gave me a boost and encouraged me to go for the SCJP. I continued to revise for about 3 months and then tried to sit it but scored just below the pass mark, despite scoring OK in all the labs and such like. Not being one to be discouraged I hit the books again, and was fortunate enough to then land a job based on my SCJA and self taught skills. Two years later, I am now a senior programmer of sorts and I am aiming to take the new SCJP exam next year. From my experience of writing and being involved in using Java for real applied programs, from small apps to Enterprise services, my perspective and understanding has increased hugely. I feel far more confident in taking the exam, and my knowledge is not just theory based on books and reading.
Now I know, there are many people who have and can pass the exam based on the books alone, but for those of us who are not in that mould, I recommend taking a step back and prioritize your learning, if there is any possibility you can get practical experience in java before you take your SCJP then do it, even if its an open source project contribution you will benefit so much, you will not just get many of those "aaah I see how it works now" moments but you will get the bigger picture as well as subconsciously getting a lot of the dreaded API firmly impressed on your brain. I couldn't grasp the collections framework at all before my job. Since my employment we use it all the time, and now its second nature to me, even generics are coming easier!
It's far harder to try and get it the first or second time round from just reading a book, even writing examples, but if you need to use it and are involved in creating whole finished applications then it starts to become clearer. Of course there will be people who may need SCJP to get that job position or experience, but its not a prerequisite for all jobs, and there is an increasing amount of need for voluntary contributions to open source projects on the web. If it is at all possible to get that practical experience do it, and then such things as API memorization are not such an issue. Of course, its impossible to get experience that covers everything, so its not a replacement for reading and test code writing, but it does compliment it tremendously.
Just ask yourself, why you want your SCJP so quickly, is it necessary to go for it straight from the book, are you learning or just memorizing? If your only memorizing, the exam must have not much value to you in the future. Yes it looks good to a prospective employer, but even better than that is the ability to understand, and utilize what you have learn't from the exam. I f you have just memorized lines in a book, then you may well get into a bit of a stick if you ever have to use that knowledge, even if you get in the high percentile this can mean nothing in the long run unless you can show you understand and can use that knowledge.
My personal mantra in regards to learning anything, I liken to learning a new language; "its one thing to learn to speak a new language, but to then think in that language is a different thing". Thus its one thing to learn Java, its rules and principles, but its another thing to know how to apply them and use them in reality. I wish all potential SCJP candidates all the best in their exams, keep using JavaRanch its by far the best forum on the net for Java, and for reading certainly Sierra & Bates has to be the first in your library, code code code, butif you can get involved somehow, do!!!
I hope this small precis can be of help. Of course its not the same for everyone, but for me it has helped my development into Java immensely considering my academic background is in Environmental law (PhD level).