No one ever pretended that shopping for anything is a rational experience. If it were, would there be Fluffernutter? Laceless sneakers? Porkpie hats? Would the Chia Pet even exist?

More and more NFL players have been willing their bodies to science so that their brains can be studied even if they die of other causes.

Confidence quickly curdles into arrogance; smarts turn to smugness, charm turns to smarm.

Humans are crude linguists from the moment of birth - and perhaps even in the womb - to the extent at least that we can hear spoken sounds and begin to recognize different combinations of language sounds.

The vexing thing about human behavior is that when we say we know we should do something, we really and truly do know it. It's hard to be 50 lbs. overweight or smoke a pack a day or feel miserable every moment you spend at work and not understand in a deep and primal way that change is in order - and that in some cases it could even save your life.

Operating-room errors hold a special terror for patients, if only because they seem like the most avoidable kind of complications. The occasional horror stories of patients who have the wrong leg removed or the wrong knee replaced generate the most headlines, as do tales of patients whose identities are mixed up entirely.

What people fear most about tragedy is its randomness - a taxi cab jumps the curb and hits a pedestrian, a gun misfires and kills a bystander. Better to have some rational cause and effect between incident and injury. And if cause and effect aren't possible, better that there at least be some reward for all the suffering.