"Fuera de un perro, un libro es el mejor amigo del hombre. Dentro de un perro está demasiado oscuro para leer."

Simplified Meaning:

Books are incredibly valuable companions for people. They provide knowledge, comfort, and joy, almost like having a good friend who is always there for you. On the other hand, trying to read inside a dog is impossible and silly because it would be too dark to see anything. This comparison humorously suggests that while books are great for reading and gaining wisdom, some things are just plainly not feasible. Imagine having a hard day and feeling lonely. Picking up a favorite book can make you feel better, almost like talking to a friend who understands you. This quote reminds us that books are always available to provide companionship and insight, unlike the inane idea of reading inside a dog. Therefore, next time you feel bored or need some advice, consider reaching for a book—it’s a reliable and enlightening friend.