在《聪明的投资者》前言评论部分，茨威格列举了几个比较有意思的实例，说明当我们认为某件事确定性非常强的时候，特别是在事情美好得难以置信的时候，我们产生的是幻觉。
1）
幻觉：
1999年前5个月，Alexander Cheung的基金就翻番了，于是他预计未来的3-5年，他可以获得50%的年化收益；在未来的20年，他可以获得35%的年化收益。
In mid-1999, after earning a 117.3% return in just the first five months of the year, Monument Internet Fund portfolio manager Alexander Cheung predicted that his fund would gain 50% a year over the next three to five years and an annual average of 35% “over the next 20 years.”
事实：
当时，20年时间段内，年化投资收益率最高的是林奇，年化25.8%。这个收益率可以将1万美元在20年增长到98万。而35%的年化，可以将1万美元在20年中增长到400万。互联网的增长给大家太美好的预期，让获得高收益的人昏了头脑。而事实上，在1999年投给他100万，到2002年仅能剩下2000块。
Constance Loizos, “Q&A: Alex Cheung,” InvestmentNews, May 17, 1999, p. 38. The highest 20-year return in mutual fund history was 25.8% per year, achieved by the legendary Peter Lynch of Fidelity Magellan over the two decades ending December 31, 1994. Lynch’s performance turned $10,000 into more than $982,000 in 20 years. Cheung was predicting that his fund would turn $10,000 into more than $4 million over the same length of time. Instead of regarding Cheung as ridiculously overoptimistic, investors threw money at him, flinging more than $100 million into his fund over the next year. A $10,000 investment in the Monument Internet Fund in May 1999 would have shrunk to roughly $2,000 by year-end 2002. (The Monument fund no longer exists in its original form and is now known as Orbitex Emerging Technology Fund.)
2）
幻觉：
1999年，Alberto Vilar的基金增长了2.48倍，于是该基金经理声称：如果不投资互联网，那么你就会跑输市场，当我在开保时捷的时候，你只能做乘坐马车。
After his Amerindo Technology Fund rose an incredible 248.9% in 1999, portfolio manager Alberto Vilar ridiculed anyone who dared to doubt that the Internet was a perpetual moneymaking machine: “If you’re out of this sector, you’re going to underperform. You’re in a horse and buggy, and I’m in a Porsche. You don’t like tenfold growth opportunities? Then go with someone else.”
事实：
如果在1999年投给他的基金1万美元，2002年会剩下1000多点。
Lisa Reilly Cullen, “The Triple Digit Club,” Money, December, 1999, p. 170. If you had invested $10,000 in Vilar’s fund at the end of 1999, you would have finished 2002 with just $1,195 left—one of the worst destructions of wealth in the history of the mutual-fund ndustry.
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股票市场能够为我们提供的收益是有限的，长期投资的最优成绩一般在15-25%，再高可能会跟短期运气有关，长期看基本不可能。
只有对很多事情有一个客观的认识，你才能客观地评价自己和自己的成绩。
很多事情看起来太美好了，好得难以置信，那你最好不要相信。
股票市场从来都不缺乏热点，每个热点持续的时间不同——有的数月，有的数年，有的甚至几十年。而成为热点的问题，往往都是多数人认为确定性强的东西，不然不会成为热点。热点热到一定程度就会成为幻觉。同时，热门的必须是高估的，至少不会是低估的——这似乎也是一个颠扑不破的真理。
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附：《聪明的投资者》前言评论的选译译文
前言之评论部分
1、注意，在本书的开头格雷厄姆就告诫我们：本书不是教会你如何跑赢市场的，没有任何书籍能够做到这一点。本书的目的是教给你以下三项重要本领：
·如何将犯下无可挽回错误的概率最小化；
·如何将取得可持续收益的概率最大化；
·如何阻止妨碍投资者充分发挥自身投资水平失控行为的发生。
Notice that Graham announces from the start that this book will not tell you how to beat the market. No truthful book can. Instead, this book will teach you three powerful lessons:
·how you can minimize the odds of suffering irreversible losses;
·how you can maximize the chances of achieving sustainable gains;
·how you can control the self-defeating behavior that keeps most investors from reaching their full potential.
2、回到九十年代后期，在那些股市繁荣的日子里，科技股的股价好像每天都可以翻倍，那时若告诉你将会亏掉所有的投资，你会觉得非常荒谬。但是，在2002年末，很多互联网和电子通信股的市值跌去了95%，有些甚至更多。
Back in the boom years of the late 1990s, when technology stocks seemed to be doubling in value every day, the notion that you could lose almost all your money seemed absurd. But, by the end of 2002, many of the dot-com and telecom stocks had lost 95% of their value or more.
3、无论你多么小心谨慎，你的投资都时不时会出现下跌。既然没有人能完全消除这一风险，那么格雷厄姆将告诉你如何管理它—以及如何控制恐慌情绪。
But no matter how careful you are, the price of your investments will go down from time to time. While no one can eliminate that risk, Graham will show you how to manage it—and how to get your fears under control.
4、从第一版开始，格雷厄姆就给出了（“聪明”的）定义—他明确地告诉我们这种聪明与智商和SAT考试成绩没有一点关系。它仅指耐心、自律和学习欲望。同时，你还要能够控制情绪并能独立思考。格雷厄姆将这种智慧解释为“是一种更强调性格而非头脑的人性特质”。
Back in the first edition of this book, Graham defines the term—and he makes it clear that this kind of intelligence has nothing to do with IQ or SAT scores. It simply means being patient, disciplined, and eager to learn; you must also be able to harness your emotions and think for yourself. This kind of intelligence, explains Graham, “is a trait more of the character than of the brain.”
5、将时间回放到1720年春天，艾萨克·牛顿爵士还拥有当时英格兰最热门的股票—南海公司股票。感觉到市场已经失控（备注：导致了牛顿的巨亏），这位伟大的物理学家哀叹道： “（自己）能够算出天体的运行轨迹，却无法计算大众的疯狂程度。”
And back in the spring of 1720, Sir Isaac Newton owned shares in the South Sea Company, the hottest stock in England. Sensing that the market was getting out of hand, the great physicist muttered that he “could calculate the motions of the heavenly bodies, but not the madness of the people.”
6、艾萨克·牛顿爵士是有史以来最聪明的人之一，这符合我们多数人对“聪明人”的认识。但根据格雷厄姆的定义，牛顿远非聪明的投资者。由于受到公众狂热的裹挟，他对市场失去了自己的判断，世上最伟大的科学家在投资上表现得像个傻瓜。
Sir Isaac Newton was one of the most intelligent people who ever lived, as most of us would define intelligence. But, in Graham's terms, Newton was far from an intelligent investor. By letting the roar of the crowd override his own judgment, the world's greatest scientist acted like a fool.
7、简言之，如果你还没有在投资上取得成功，那不是因为你愚蠢，而是因为，如牛顿爵士那样，你还没有形成有效的情绪控制策略，那才是股市致胜的关键。
In short, if you've failed at investing so far, it's not because you're stupid. It's because, like Sir Isaac Newton, you haven't developed the emotional discipline that successful investing requires.
8、如果在九十年代，股价到了看似 “没有最高只有更高”的地步；那么在2003年，我们已经走到了股价看似“没有最低只有更低”的境地。钟摆，如格雷厄姆所深知的那样，开始从非理性乐观摆向非理性悲观。
If no price seemed too high for stocks in the 1990s, in 2003 we've reached the point at which no price appears to be low enough. The pendulum has swung, as Graham knew it always does, from irrational exuberance to unjustifiable pessimism.
9、聪明的投资者会认识到：当股价上升时，风险会变得更大而不是更小；相反，当股价下降时，风险会变得更小而非更大。聪明的投资者会惧怕牛市，因为牛市使你买入股票的价格更贵。相反，（只要你手头留出足够的资金）你应该喜欢熊市，只有熊市才能让股票重新变得便宜。
The intelligent investor realizes that stocks become more risky, not less, as their prices rise—and less risky, not more, as their prices fall. The intelligent investor dreads a bull market, since it makes stocks more costly to buy. And conversely (so long as you keep enough cash on hand to meet your spending needs), you should welcome a bear market, since it puts stocks back on sale.
10、所以振作起来：牛市的逝去并非像每个人想象的那样是件坏事。随着股价的下跌，现在（2003年）的市场已经达到一个更安全—并更理性—的节点，是时候开始积聚财富了。
So take heart: The death of the bull market is not the bad news everyone believes it to be. Thanks to the decline in stock prices, now is a considerably safer—and saner—time to be building wealth.