Or, to put it another way, you often don't really understand the problem until after the first time you implement a solution. The second time, maybe you know enough to do it right. So if you want to get it right, be ready to start over at least once [JB].
http://www.catb.org/~esr/writings/cathedral-bazaar/cathedral-bazaar/ar01s02.html


12. Often, the most striking and innovative solutions come from realizing that your concept of the problem was wrong.
12. Often, the most striking and innovative solutions come from realizing that your concept of the problem was wrong.