But as the market recovered, many workers seemed to forget that important lesson.
"The market may not recover for another four or five years."
The market recovered a bit the following day but ended the week down 13.4 percent.
Having said all that, the thing that's most striking about what happened yesterday is how quickly the market recovered.
"I can't imagine we will see the market recover before the economy," he said, and that may not happen until well into 1993.
The market dropped 33 points in 10 minutes, but then quickly recovered.
What happens if the market doesn't fully recover for a long time?
It is not clear, however, how quickly the market will recover.
But even with the gains, the market has recovered only a little more than a third of the ground it lost last week.
But the market has been recovering in the last three years, and the same car would be worth "around $7 million today," he said.