Every wall is a door.

The illiterate of the 21st century will not be those who cannot read and write, but those who cannot learn, unlearn, and relearn.
- Alvin Toffler

Every wall is a door.
- Ralph Waldo Emerson

Believe nothing, no matter where you read it, or who said it,
no matter if I have said it,
unless it agrees with your own reason and your own common sense.
- The Buddha

I leave no trace of wings in the air, but I am glad I have had my flight.
- Rabindranath Tagore

Doubt is not a pleasant condition, but certainty is absurd.
- Voltaire

Tradition is the illusion of permanence.
- the Woody Allen movie Deconstructing Harry