I once did a punishing three-day hike around an island - almost all walking on sand with the loss of propulsion that brings, as well as sunlight reflected up into your face all day.
At the end of the first day, the rest of us were exhausted. The hike leader, a massive ex-army guy, promptly opened his pack, pulled out a camp chair, sat down grandly, pulled out a bottle of champagne and uncorked it, and pulled out a tin of caviar ... and proceeded to drink the whole bottle and eat the whole tin while we cooked up our Constipation House meals.
Prick.