Most of us have participated in the trust exercise in which one person falls back and is caught by a peer. Even if the catch is made a hundred times in a row, the trust is broken forever if the friend lets you fall the next time as a joke. Even if he swears he is sorry and will never let you fall again, you can never fall back without a seed of doubt.

Teach Like Your Hair's on Fire: The Methods and Madness Inside Room 56 (ed. Penguin, 2007) - ISBN: 9781101201916