“Don't spend time beating on a wall, hoping to transform it into a door.”

“Every wall is a door.”

“If you beat your head against the wall, it is your head that breaks and not the wall.”

“There comes a time in a man's life when to get where he has to – if there are no doors or windows – he walks through a wall.”

“I want to spend my time with people who don't look to be respected. But such good people won't want to spend their time with me.”

“Build a better mousetrap, and the world will beat a path to your door.”

“Knowledge is the key that unlocks all the doors. You can be green-skinned with yellow polka dots and come from Mars, but if you have knowledge that people need, instead of beating you, they'll beat a path to your door.”

“The world is the closed door. It is a barrier. And at the same time it is the way through.

Two prisoners whose cells adjoin communicate with each other by knocking on the wall. The wall is the thing which separates them but it is also their means of communication. … Every separation is a link.”

“While the heart beats, hope lingers.”

“After a few weeks of this she'd spend a whole day weeping, beating at herself as if on fire.”