No man ever steps in the same river twice,
for it's not the same river and he's not the same man.
–Heraclitus
You wouldn't review an album on one listen. Or spend a single day in a city and declare "I've seen it." But folks will read a book once, even one they love, and call it a day. If you want to Live Más: read a book more than once.
Some say life is too short to re-read books. As though our time on Earth is to maximize the novelty of our sense-data. If life is about anything (and this is debatable), it is about making meaning of our experiences, not merely collecting them. Life isn't a shopping spree, it's a creative workshop.
There are many reasons to re-read a book. You might uncover something you missed the first time. You might sink a valued concept or passage deeper into your mind. You might change your mind about the book. You might learn something about yourself.
A book, like all art, is a statement declared at a moment in time. What a gift in an endlessly changing universe. When you re-read a book, you can experience how you've changed since the last time you read it. When you read a book more than once, you are reading yourself. You are meditating.
Reading is not about jamming words into your mind but what chemicals in the System of You the examined (and re-examined) text gives rise to, and how. A book is the cheapest drug you'll ever do, and the only that gets more potent when you do it again.