Toxins love to get you while you're young. Lead, mercury, secondhand smoke and sundry other environmental nasties do a lot more damage when tissue is immature, vulnerable and growing than when it's mature and comparatively fixed.

What makes spinal-cord injuries as devastating as they are is that everything about them plays out in absolutes: they are instantaneous, utterly disabling and horribly permanent.

When it comes to raising civilized kids there are no hard rules, but there are two things on which most parents agree: Boys are generally wilder than girls, and adolescents are wilder than kids of any other age. If you've got an adolescent boy, you're in the sweet spot for trouble.

Older fatherhood isn't all bad: testosterone rates drop about 1% per year as men age, making them less reactive and more patient, and a professionally established middle-aged man is likely to have more time and money to devote to his kids than a twenty-something who's just getting started.

Never mind what you've heard. Halle Berry was not the first black woman to win an Academy Award for Best Actress. She was actually the 74th white one. And never mind all this talk about America electing its first black President; Barack Obama is actually the 44th white man to hold the job.

There's no such thing as downtime for your brain.

Athletes often start life at the opposite end of the wealth and prestige spectrum, but as soon as they exhibit an unusual talent for swinging a bat or sinking a free-throw they may find that the rules have been suspended for them. They are waved through school and into the pros, and incidents of bad behavior are overlooked or covered up.