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.
When a thousand men live together, then each man lives a thousand lives.
And finally, close to the same meaning:
The world is a book and those who do not travel read only one page
Reading is then the only way