How You Know

Paul Graham’s essay How You Know argues that reading’s value lies not in what we consciously remember, but in how it reshapes our mental models.

The Memory Problem

We remember surprisingly little from books we’ve read multiple times. This seems wasteful until reconsidered through a different lens.

The Compilation Metaphor

“Your mind is like a compiled program you’ve lost the source of. It works, but you don’t know why.” Reading reshapes your internal models even after explicit memories fade.

Multiple Readings Matter

Since your brain “compiles” information differently depending on your current state, rereading important books is worthwhile. You’ll extract fresh insights each time.

Future Implications

As technology advances, people may replay experiences intentionally—not to relive pleasure, but to extract fresh insights from them.

My Takeaway

The harvest from reading is smaller in observable memory but larger in invisible mental development. Read to change how you think, not to accumulate facts.