Never take for granted that the receiver has the same reality as you. Never take for granted that the receiver will interpret the message the way it was intended. Communication is not an absolute, finite thing. Always assume as many different realities exist as there are different people involved in the communication.

— Christopher Hadnagy and Paul Wilson, Social Engineering

Doctors troubleshoot the human body—they never got a chance to debug it. (It took God one day to design, prototype, and release that product; talk about schedule pressure! I guess we can forgive priority-two bugs like bunions and male pattern baldness.)

— David J. Agans, Debugging

By its very nature, a product process “fights the last war,” encouraging tactics that have worked in the past and discouraging those that have failed. Hence for the product addressing a new war—a totally new need or mode of operating—both kinds of tactics may be irrelevant.

— Frederick P. Brooks Jr., The Design of Design

…floating-point math libraries that haven’t changed in forty years—they don’t need to change, because math doesn’t change. But in almost every other domain, especially when you have customers, change is a fact of life.

— Gene Kim, The Unicorn Project

The technology, the surrounding organization, and the traditions of the craft conspire to define certain items of paperwork that a project must prepare. To the new manager, fresh from operating as a craftsman himself, these seem an unmitigated nuisance, an unnecessary distraction, and a white tide that threatens to engulf him. And indeed, most of them are exactly that.

— Frederick P. Brooks Jr., The Mythical Man-Month