An idea that was characteristic of Albert Einstein has been advanced by Richard Feynman, also a physicist. To learn something and remember it, simplify. Make it so simple you can explain it to your grandchild (provided he has reached adolescence).
Simplicity seems to be the art of Creation. The way to Heaven can be understood by a child of three, and the laws of survival, if not confused, by a child in her preteens.
Don’t dither over the meaning of life; it is apparent to most people your age. That is people who really want to know, all obfuscation aside.
Civilization 