How Did You Understand But Not Necessarily Memorize The MCAT Material?

I plan on taking the MCAT next year in 2018 around the month of January. I just recently (About a week ago), finished reading all of the Kaplan MCAT books from the 7 book set titled "Kaplan Complete 7 Book Subject Review 2015"

As a human being it is unrealistic and impossible to memorize every bolded term, pathway, reaction, principles, terminology etc from all of the books. It is even impossible to attempt a memorization of ~75% of the material. I recently took a full length MCAT from the Kaplan site without it being timed. I did this to essentially analyze every answer choice for questions which completely confused me. I used my Kaplan books and online resources as tools to guide me to my answer.

Here is the issue. I feel extremely overwhelmed with the amount of information I need to deeply understand for many of the questions. In many instances I might be able to recall the general information related to the question, but struggle to recall the specifics of the information which is needed to answer the question. And when I do have to look up the specific information for the question and find it, I tend to say "Oh yeah.... I remember that," but in my mind I keep thinking that, that specific information is a very small detail I just happened to forget. Afterwards I tell myself, "I know that specific information now, but how will I recall the plethora of small details for additional concepts that surround the topic for that question which was not asked?" From there I begin to think about every subject covered in the MCAT and get overwhelmed.

QUESTION - How were you able to efficiently absorb and understand the MCAT material regardless of the subject, without having to memorize the information? (By "Without memorizing," I mean you did memorize the material to some degree, but you memorized it in a way where you did not have to necessarily memorize a plethora of detail for each concept).

Please Note: I am not implying that memorizing material should be taken out of the picture 100% and I should solely focus on understanding. I know memorizing is a part of understanding the material, but how do you go about it which this much information?

Thank you! I deeply apologize for the rant, I am just overwhelmed and stressed.