The most common cause of low prices is pessimism - some times pervasive, some times specific to a company or industry. We want to do business in such an environment, not because we like pessimism but because we like the prices it produces. It's optimism that is the enemy of the rational buyer.
When it comes time to protecting the homeland, the United States of America must be right 100 percent of the time. And the enemy, which desires to strike us again, only has to be right once.
Still, I have been no one's enemy but my own. My easy nature, either in drinking or anything else, was always ready to submit to persuasions of profligate companions, who often led me into snares.
It is sufficient to estimate the enemy situation correctly and to concentrate your strength to capture him. There is no more to it than this. He who lacks foresight and underestimates his enemy will surely be captured by him.