Speaking from personal experience only, the brain is practically unlimited in its capacity for information storage, but the ability to index and access this information takes effort in the form of study and using the information. Don't worry about "overloading" your memory, just concentrate on accessing the necessary information through exercises.
What you have to develop is a mental "pidgeon hole" system for the information before you can readily use it. Related information gets filed in association, and you get to determine the relationships. (At least that seems to be the way my head works.)
Later, as you get older, you will find that details of your knowledge and understanding leak away at a faster rate, but it is still available if you wish to exercise it, and you can still learn new stuff.
The preceding bit about unconscious competence refers to the skills we have integrated into ourselves. It is also the stuff that makes PIO a reality. Once you have learned this type of reaction, it stays with you a long time, for better or for worse.