Plan to throw one (implementation) away; you will, anyhow.

Adjusting to the requirement for perfection is, I think, the most difficult part of learning to program.

Originality is no excuse for ignorance.

The hardest single part of building a software system is deciding precisely what to build.

The hardest part of the software task is arriving at a complete and consistent specification, and much of the essence of building a program is in fact the debugging of the specification.

System debugging, like astronomy, has always been done chiefly at night.

The first step toward the management of disease was replacement of demon theories and humours theories by the germ theory. That very step, the beginning of hope, in itself dashed all hopes of magical solutions. It told workers that progress would be made stepwise, at great effort, and that a persistent, unremitting care would have to be paid to a discipline of cleanliness. So it is with software engineering today.