A reader lives a thousand lives before he dies. The man who never reads lives only one

While George R.R. Martin wrote this quote, there‘s previous mentions of similar phrasing such as:

A dreamer lives a thousand lives, a hero lives but one.
Marcus Omer

When a thousand men live together, then each man lives a thousand lives.
Willard Waller

And finally, close to the same meaning:

The world is a book and those who do not travel read only one page
St. Augustine

Reading is then the only way