“Program testing can be used to show the presence of bugs, but never to show their absence!”

“Picture postcards never show the bugs,” I told her. “Stinging ants, wasps, fleas, roaches the size of your hand. Postcards never show the heat.”

“Hard work, sacrifice and focus will never show up in tests.”

“The salat can be made up for, but there is no making up for false show or outward worship without presence.”

“In a magic show, mystification is a good thing, but it is hardly to be commended in an economic program.”

“Experience shows that the success of a programming course critically depends on the choice of these examples.”

“Imagine creating a huge software program that can only be tested in little pieces on a computer that is slightly different from what it is supposed to run on. However, when you do run it as a whole on the actual computer for the first time, it must run almost flawlessly without a single significant bug. When is the last time you saw a software program do that?”

“The past cannot survive in your presence. It can only survive in your absence.”

“To the designer of programming languages, I say: unless you can support the paradigms I use when I program, or at least support my extending your language into one that does support my programming methods, I don't need your shiny new languages. […] To persuade me of the merit of your language, you must show me how to construct programs in it.”

“I think all of us are always five years old in the presence and absence of our parents.”