memory decline and academia
You can use note taking to both save the information you later want to recall, and, more importantly, reinforce the learning that helps you recall it. 

There is evidence that hand written notes are best for memory enhancement as they engage the brain in a different way than typing (or certainly more than cut-paste). 

But you can go an extra step. You can, at a somewhat later date, summarize your notes, which, again, reinforces the learning. 

And there is no reason that you can't also capture your original notes and/or summaries in some computer media for keyword searching and such. 

This personal database of past readings and thoughts about those readings is better for recall than, say, Google, which searches a larger space than you are interested in and so comes up with un-useful hits. 

But the key to it, is to use reinforcement tricks (hand written notes, etc.) so that deep learning is achieved and recall is more likely. 

Personally, I prefer taking original notes on index cards. You can always carry a pen and a few cards for making quick notations and for noting questions you might have so that they can be explored later. The cards can then serve as the basis of summaries. See this answer to an unrelated question for more on the concept of the Hipster PDA.



Of course this technique works best if you start it before you need it. But it isn't ever too late. There is a Chinese proverb: The best time to plant a tree is forty years ago. The second best time is right now.