But back to business:
Tom Stafford has a post up at Mind Hacks detailing the neurological effects of learning:
When you learn a new thing, or get a surprise, there is a shot of a chemical messenger in your brain called dopamine. Dopamine is famous among neuroscientists for its involvement in the reward and motivation systems of the brain.
The reason for this electro-chemical connection between learning and drugs of reward is that our brains have obviously been designed to find learning fun.
Personally, I think this lends credence to less authoritarian educational approaches, such as the Montessori method and unschooling. On the other hand, that could just be my libertarian bias.