When I graduated from college, I switched
from trying to remember the everything I read to trying to see the book's
ideas as they relate to my worldview. Not too long after that, I realized
that I was losing the ability to make substantive comments about many books
that I had read, because I only remembered my worldview. I no longer knew
where the pieces came from. So I started keeping some notes on books I read.
Now, I basically keep a hundred words or so, a book snapshot, on most of the books I read.