A couple of weeks ago, I grabbed a book off my bookshelf because I wanted to quote a passage from it in something I was writing. I underline passages so I can find them under such circumstances. I found the passage I was looking for and for some reason I had written a date next to it in the margin. Seeing the date gave me context. It helped me remember what was going on in my life when I read that passage.
It gave me an idea to begin writing the date in the margin of every book I read at the beginning of each reading session. I did that as I read Open by Andre Agassi. I'm doing it now as I read A Million Miles in a Thousand Years by Donald Miller. In the years to come, as I flip through these books I'll have context for the passages that spoke to me and I think they'll mean more to me.