I remembered that I awarded one dollars to someone who ate last piece of watermelon on Feb 13, 2011, the similar size as ours yesterday.
Walking over 30 KM with 1500 meters ascent and over 1500 meters descent for 9 hours including 1 hr lunch break and severl short breaks yesterday and 'easy' walk on Giant Stairway on Feb 13, 2011 make some difference.