During undergrad school I learned some valuable study techniques and habits that have enabled me to do well in my studies. Applying them has saved me time, developed my practical learning skills, knowledge retention and application. My Histology and Embryology Professor, Dr. Boyd, always stressed the importance of "need to know" information. These are what he considers to be pearls. As Dr. Boyd would say "Your pearls are the answers to your exam questions." I have proven it to be true time and time again. You don't need to know/learn every bit of information you are given. Aside from the fact that it is almost impossible, you need to "find your pearls and know them." What is a pearl? This is the point of the story, the gist of the article or the factors that lead to why 2+2=4. The need to know information, not the nice to know stuff. That's it!
There must always be relevance and meaning in the things we learn. Don't try to learn everything, try to learn what is relevant and meaningful.