401K Value Decline and Can You Endure it

A guy at work told me that he switched 100% of his 401k money into CDs, and he did this when the Dow was 35% higher than it is. First I am not sure this is true. Second, if he can do this twice, he should be running a mutual fund, and not working at BASF. Third this made me feel like, "Am I stupid, why did I not sell out too?"

One reason I did not sell is because I finished reading, Fooled by Randomness by Nassim Nicholas Taleb and Intelligent Asset Allocator by William Bernstein -- two academic economists. They keep repeating that the average active investor does not consistently beat the market. They would say that it is foolish to try to "time the market," and that these kind of events just average themselves out. Nassim Taleb says that just because the market is gone down, your percent ownership in the companies is still the same -- which feels kind of hollow.  

I heard a news report that most mutual funds misread the recent downturn and are down worse than the main indexes. 

William Bernstein would have one sell safe bonds, and use them to buy beat-up stocks. One knows at some point that will make sense. 

Finally, if the guy at work had sold his stock, and the strategy had not worked, he never would have told me about it. One only brags about successes. One hides failures, usually even from oneself.