When you think of terms such as school, college, and university and combine it with the word study, do you get a good feeling on your inside, or does it sound terrible, boring, and tiring? Often, that feeling is influencing your actual efficiency as you study.
It is well known that the best way to learn something is if you do so while enjoying what you are doing. If you have to build a house in the garden, then the best way of learning the techniques is to do it together with someone who has the skills and the knowledge, and together with them, you learn while you do it, and you actually enjoy the work.
Maybe you want to impress a girl by showing off your knowledge about the brain? Well, that is for sure giving you the motivation to learn, and if you do so with joy (which you should), then your brain will be much more effective and it will be easier for it to receive the information coming your way!
So, try to find motivation whenever you study and make the motivation more than a good grade. Visualize something on the other side of the knowledge that will make it worth it. That will help you when it might be hard, complicated, and you feel like giving up, or just getting satisfied with understanding it a little bit.