'Good times' don't last forever....yet, people want to believe they do.
Like the turkey who believes good times are common place until the third week of November, most people expect the good times to roll on. And so, they only see what they are looking for. Even their stockbroker won't tell them that "when in doubt, get out."
Yet, if you understand that there are business cycles, you look for the unexpected and thus see the unexpected when it surfaces....long before others do. 
Mike Jay is a futurist and makes his living by helping others see what they are blind to. In his new book, Jay answers the question:
In tough times, what risks should we avoid and which should we snap up?
Our ability to recognize and react to today's unexpected events is key to both our growth and survival. As business entrepreneurs, we must have enough knowledge to plan and anticipate, yet enough street savvy to know when things are going unusually right or unusually wrong.
We're talking here about really big surprises -- like discovering that one of your products is selling much better than expected -- and you don't know why ...or... discovering that you are selling to the wrong customers ...or... that your product or service needs to be revamped from top to bottom ...or... even discovering you are in the wrong business.
What comes next could be scary. When the social mood trend changes from optimism to pessimism, creditors, debtors, producers and consumers change their primary orientation from expansion to conservation. As debtors and potential debtors become more conservative, they borrow less or not at all. As producers become more conservative, they reduce expansion plans. As consumers become more conservative, they save more and spend less. A downward "spiral" begins, feeding on pessimism just as the previous boom fed on optimism.
The resulting cascade of debt liquidation is a deflationary crash. What better reading material is there than "Upping the Downside" by Mike Jay....as we in the U.S. begin the long climb out of a period of depression, or at the least a few years of recession?
When the going gets tough, it's time to get going.