theory of constraints
one of my failings is that i don't always do a good job of *properly* optimizing my code. i often commit the common sin outlined by Donald Knuth so long ago:
"Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. We should forget about small efficiencies, say about 97 percent of the time: premature optimization is the root of all evil."
here's a nice article on the Theory of Constraints that reminded me how important it is to do this correctly: How Can Theory of Constraints Help in Software Optimization?.