In the film The Empire of the Sun, there is a vivid depiction of desperate thirst. In the chaos of World War II in China, the young son of a wealthy British expatriate is separated from his family. There is no one to care for him. The boy returns to his home and lives for a while on whatever food has been left behind. But his supplies run out, and he is desperately thirsty. Even the swimming pool on the family estate has run dry. The boy returns to the kitchen, which is littered with empty cans, and he feverishly licks every last one to the very bottom.
That is a picture of what it is like to live in this world and be thirsty for God. We are thirsty people. We go through this life panting after something, anything, that will slake our thirsty souls.