Narcissism, like the other personality disorders, is a condition that's known as ego-syntonic. In other words, the paranoid person really does believe that people are after him, and the narcissist really does believe that he or she is better than or more entitled than other people, and truly doesn't see why that's not the case.

When we're awake, cortisol can fragment memories - one reason eyewitness crime scene accounts are so unreliable. But at night that very fragmentation allows creative recombinations of ideas.

Tamerlan Tsarnaev is telling no tales. The older of the two brothers who committed the Boston Marathon bombings was likely the one who planned the attack, but when he died in a shootout with police just days after the blasts, his thoughts and motivations vanished with him.

Marriage is a lot of things - a source of love, security, the joy of children, but it's also an interpersonal battlefield, and it's not hard to see why: Take two disparate people, toss them together in often-confined quarters, add the stresses of money and kids - now lather, rinse, repeat for the rest of your natural life. What could go wrong?

When our culture shifts, it tends to overcorrect, throwing out everything associated with an era we've moved past, rather than saving what was good and combining it with what is new.

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.

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.