3 exercises in discretion.

When somebody tells you they're driving to the clinic for a stress test, that's the wrong time to say that if they'd regularly walked to the clinic they probably wouldn't need any stress test. You may remember exactly how many release-your-inner-millionaire books a friend has ever bought. There's no good time to mention that number, ever. And listen. Someday, let's suppose somebody gets up in your face all belligerent and asks, “You think I care what you think of me?” That's probably a bad time to point out that they're asking your opinion of them, right there.