Thirst For Knowledge May Be Opium Craving
[excerpts:]
The "click" of comprehension triggers a biochemical cascade that rewards the brain with a shot of natural opium-like substances, said Irving Biederman of the University of Southern California. He presents his theory in an invited article in the latest issue of American Scientist.
[...]
The brain's craving for a fix motivates humans to maximize the rate at which they absorb knowledge, he said.
"I think we're exquisitely tuned to this as if we're junkies, second by second."