When debugging, novices insert corrective code; experts remove defective code.

If you cannot grok the overall structure of a program while taking a shower, you are not ready to code it.

When teaching a rapidly changing technology, perspective is more important than content.

When building a complex system, having crackerjack programmers (who can make any design work, even a bad one) can be a liability. The result, after lots of effort, is a working system that cannot be easily maintained or upgraded. Good -but not great- programmers would fail early, causing a realization that the system must be redesigned, and then reimplemented. The extra cost is paid once, early in the system's cycle (when it is cheap), instead of repeatedly paid late in the system's cycle (when it is more expensive).

Code should run as fast as necessary, but no faster; something important is always traded away to increase speed.

The discipline of programming is most like sorcery. Both use precise language to instruct inanimate objects to do our bidding. Small mistakes in programs or spells can lead to completely unforseen behavior: e.g., see the story, "The Sorcerer's Apprentice". Neither study is easy: "...her [Galinda's] early appetite for sorcery had waned once she'd heard what a grind it was to learn spells and, worse, to understand them." from the book "Wicked" by G. Maguire.

The three most important aspects of debugging and real estate are the same: Location, Location, and Location.