The 21 days was in November, 2010. You are absolutely correct in what you say about the importance of smart re-feeding. I use long fasts as natural resets, and utilize the newly fresh perspective to further the healthy lifestyle which I have been building. The idea that it can't be a diet, but rather a lifestyle is EXACTLY the perspective I have on it as well. You MUST know yourself and build a healthy habit of eating which you can happily sustain.
I fast becsuse, after a veritable ton of research I have come to believe that through yearly fasting and a natural, healthy and fulfilling style of eating in between fasts that I will be helping myself live a longer and healthier life. Weight loss is just a side effect of fasting for me....as well as the fact that I love getting down to super low body fat and then rebuilding a bunch more muscle. Its always nice to have immediate results show.