Wow, did you ever hit the nail on the head. I've been saying this for a long time (edit: e.g. http://news.ycombinator.com/item?id=96186 http://news.ycombinator.

Wow, did you ever hit the nail on the head. I've been saying this for a long time (edit: e.g. http://news.ycombinator.com/item?id=96186 http://news.ycombinator.com/item?id=96186, http://news.ycombinator.com/item?id=173949 http://news.ycombinator.com/item?id=173949), wondering why I'd never run across anybody making what seems an obvious point. At last I have! The important decisions around performance have to do with design, not optimization. Knuth's original principle was quite explicit: forget about most small efficiencies. But people commonly use it to justify not thinking about large ones. "Don't micro-optimize prematurely" somehow got changed into "don't think about performance until the end of the project".