I said fasting is learning about your body and mind and part of that is learning our 'weaknesses' and being prepared to combat them better next time. When I first started fasting I could go for no longer than 1-3 days then I would trot on down to the chip shop with the family and enjoy the fried chips (no fish I was already vegetarian). The taste was just beyond compare after not eating for a day or three and the temptation was just too great. The main difference with my successes last year is that I focussed on how to break the fasts, so no matter how long I ended up fasting for I was always prepared to break the fast correctly. This helped me continue my goal of changing my body's eating habits/cravings and also prepare the body for the next fast.
Remember no fasting attempt is ever a failure, just one step along the journey to your success.