three guys decide to cross the Simpson desert ...
First one takes as much fruit as he can carry cause fruit is a good source of water and nutritien ...
Second guy takes as much water as he can carry ...
Third guy drags along a car door .
After 5 days they have eaten all the fruit , and drunk all the water and are now dying of thirst.
First guy stagers forward and falls in a heap into the hot sand , second guy is also strugling ... They both look back at third guy still draging the car door : first guy yells out "hey third guy , I brought fruit here and second guy here brought water ... but why on earth did you bring that car door ?"
third guy yells back "well it's for when I get hot : I can wind the window down and get some cool air !"