At public broadcasting, we call commercial broadcasting the dark side. We have the luxury of time, of not having those ever- looming commercial interruptions. We take ourselves pretty seriously. Some people say that's not a good thing. I think it's great.

I'm a preacher's kid, and we were always told, Act right all the time, because someone's always watching.

Truth is, in fact, an elusive concept. It depends almost entirely on where you are standing at the time. It is a human instinct to confuse belief with truth.

Moderating a debate means spending more time with briefing books than with your children. It means writing and rewriting and rephrasing. It means finding a way to be alert enough to notice when your question goes unanswered and nimble enough to decide what you will do about that on the spot.

Once they have actually left office, we seem to grow fonder of our ex-presidents - and they of each other. That's why so many sighed in approval at Michelle Obama's public display of affection with George W. Bush at last month's dedication of the National Museum of African-American History and Culture.

It gets tiresome after a while.