As MBA professors endlessly tell their students, companies do best when they stick to what they do well. There's a reason Apple doesn't make blenders. There's a reason Haagen-Dazs doesn't sell meat. And there's a reason drug companies should focus on saving and improving lives - not jeopardizing them.

There may be no more-radioactive term in the English language than what we now almost always refer to as the 'n-word' - itself a coy means of linguistic sidestepping that is a sign of how perilous it is to utter the thing in full, even in conversations about language.

Older siblings get more total-immersion mentoring with their parents before younger siblings come along. As a result, they get an IQ and linguistic advantage because they are the exclusive focus of their parents' attention.

At the root of the shy temperament is a deep fear of social judgment, one so severe it can sometimes be crippling. Introverted people don't worry unduly about whether they'll be found wanting, they just find too much socializing exhausting and would prefer either to be alone or in the company of a select few people.

Spending $1 for a brand new house would feel very, very good. Spending $1,000 for a ham sandwich would feel very, very bad. Spending $19,000 for a small family car would feel, well, more or less right. But as with physical pain, fiscal pain can depend on the individual, and everyone has a different threshold.

A fishnet is made up of a lot more holes than strings, but you can't therefore argue that the net doesn't exist. Just ask the fish.

Indeed, the best way to think of willpower is not as some shapeless behavioral trait but as a sort of psychic muscle, one that can atrophy or grow stronger depending on how it's used.