Morgan Housel has another excellent column on the common volatility of stocks, including the best performing stocks in the past 20 years. He includes the classic Munger quote:
"This is the third time that Warren [Buffett] and I have seen our holdings in Berkshire Hathaway go down, top tick to bottom tick, by 50%. I think it's in the nature of long-term shareholding that the normal vicissitudes in markets means that the long-term holder has the quoted value of his stocks go down by, say, 50%.
In fact, you can argue that if you're not willing to react with equanimity to a market price decline of 50% two or three times a century you're not fit to be a common shareholder, and you deserve the mediocre result you're going to get compared to the people who can be more philosophical about these market fluctuations."
Read the entire article here: http://www.fool.com/investing/general/2016/02/09/the-agony-of-high-returns.aspx