"Amdahl's law is a bitch."

(When you're trying to improve something, focus on the parts that contribute most to the problem. If something takes 10% of your time and you make it a million times faster, that still only gives you about a 10% improvement overall. Fun fact: in the US federal budget, only about 18% of it is discretionary spending -- the rest of it is mandatory spending on things like interest and Medicare, so a big push to remove bridge-to-nowhere pork really wouldn't do much to reduce spending. Or a more personal example: did you know that by far most of the power that low-power CPUs use is spent just moving data across the chip, and not on logic? And yet people still spend countless man-hours on making the logic use less power, and getting diminishing returns. People can have a hard time seeing Amdahl's law even when it's staring them in the face.)