Learning has an evolutionary purpose: Among species, individuals that adapt to their environments will succeed. That's why your brain more easily retains important or surprising information: It takes very little effort to remember that the neighbor's dog likes to bite. Remembering the dog's name is harder. One ensures safety, the other is just a random fact....

Learning has an evolutionary purpose: Among species, individuals that adapt to their environments will succeed. That's why your brain more easily retains important or surprising information: It takes very little effort to remember that the neighbor's dog likes to bite. Remembering the dog's name is harder. One ensures safety, the other is just a random fact....