Be able to analyze statistics, which can be used to support or undercut almost any argument.

Be able to tell whether garments that look good on the hanger actually look good on you

A 45-year old looks a lot like a 25-year old who's been out all night. And feels just as good about having survived the experience.

Know how and how much to tip people who expect gratuities, even in the case of poor service.

Geometry is beautifully logical, and it teaches you how to think and prove that things are so, step by step by step. Proofs are excellent lessons in reasoning. Without logic and reasoning, you are dependent on jumping to conclusions or - worse - having empty opinions.

I love having ten times as much stuff to do as I can possibly find time to do. That way, I can pick the one-tenth that I want to do most. But if I only have enough to just occupy all my time, I'm stuck doing all of whatever stuff it happens to be.

An error becomes a mistake when we refuse to admit it.