Believe the terrain, not the map

Trivia rarely affect efficiency. Are all the machinations worth it, when their primary effect is to make the code less readable?

... it is a fundamental principle of testing that you must know in advance the answer each test case is supposed to produce. If you don't, you are not testing; you are experimenting.

Believe the terrain, not the map

Another effective [debugging] technique is to explain your code to someone else. This will often cause you to explain the bug to yourself. Sometimes it takes no more than a few sentences, followed by an embarrassed "Never mind, I see what's wrong. Sorry to bother you." This works remarkably well; you can even use non-programmers as listeners. One university computer center kept a teddy bear near the help desk. Students with mysterious bugs were required to explain them to the bear before they could speak to a human counselor.

C is a razor-sharp tool, with which one can create an elegant and efficient program or a bloody mess.

Do what you think is interesting, do something that you think is fun and worthwhile, because otherwise you won't do it well anyway.