Zeta Woof

Neuroscientist Joe Z. Tsien was messing around with mice.

While ordinary mice quickly developed the habit of pressing a lever to get a food pellet (leading to overeating), the mutant mice stopped pressing the lever as soon as they felt full.

These mice were missing a protein known as an NMDA receptor on their dopamine neurons. Normally, these receptors help to generate a big electrical response when an animal is repeatedly exposed to a rewarding cue, such as a food pellet....

Big response: normal mouse.

A few years ago, he created a mouse strain with too much of the receptor and created a freakishly smart rodent—Mr. Tsien nicknamed it Doogie—that could learn and remember far better than a normal mouse.

Bigger response: freakishly smart mouse.

He has also showed that younger brains have significantly more of this receptor, which is why they absorb new information and acquire new routines so much more rapidly.

The point is, Doogie got a kick out of learning new things. He wasn't doing it for practical reasons — who needs another food pellet?
He was into it for the big electrical response. Doogie liked learning because learning was fun.