It is not like the knowledge-based exams from high school and college, where the emphasis was on memorizing and regurgitating information. Medical schools can assess your academic prowess by looking at your transcript. They use the MCAT to assess whether you possess the foundation upon which to build a successful medical career. Though you certainly need to know content to do well, the stress is on thought process, because the MCAT is above all else a thinking test. The test's power comes from its use as an indicator of your abilities.
Good scores can open doors.
Your power comes from preparation and mindset, because the key to MCAT success is knowing what you're up against. Add in the administrative details at both ends of the testing experience, plus three breaks and you can count on being in the test room for well over six hours.