Jean Chatzky

Optimism is an expectation that good things are going to be plentiful. The wealthy generally have the sense that life will bring good rather than bad outcomes. That doesn't mean they believe that good things will be omnipresent, but that they will outnumber the not-so-good.

Generally, there are three rules when it comes to borrowing money: You need to have good credit, proof of income and cash for a down payment. Most people have the first two, but it's the third that trips them up. And nowhere does that come into play more than the mortgage market.

If you live in a yard sale kind of neighborhood - in good weather, most neighborhoods are crawling with them on weekends - do a sweep to see what the competition is charging. No one is going to buy your $7 book if they can get it down the block for $1.

By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.