In the programming world, one of the most widely repeated maxims is, "Premature optimization is the root of all evil." Having found this to be one of the most well-intended yet misunderstood pieces of advice in the history of the Universe, I was all set to write a blog about why. Unfortunately, for me, a quick trip to Wikipedia led me to this article: The Fallacy of Premature Optimization, by Randall Hyde, which said everything I intended to say, and more, and did so more eloquently that I could ever hoped to have (although I might have put in some better jokes).
So the only thing I really have to add to that article is the following crude attempt at marketing: let's put a little spin on that phrase and turn it around! Whenever you hear "premature optimization is the root of all evil", retort (politely) with "but proactive optimization is the root of all goodness."