Let's face it, if there were 10 people like me in the world, we wouldn't have time to read each other's books. - Donald Knuth

People who are more than casually interested in computers should have at least some idea of what the underlying hardware is like. Otherwise the programs they write will be pretty weird.

The important thing, once you have enough to eat and a nice house, is what you can do for others, what you can contribute to the enterprise as a whole.

A good technical writer, trying not to be obvious about it, but says everything twice: formally and informally. Or maybe three times.