Rather than sit on the sidelines, my worries are motivating me to search for businesses that can thrive in spite of an adverse economy. Last week, I put new money to work by investing in stocks. And I'm sure critics would call me naive for investing at a time like this. But I don't consider myself naive. To the contrary, if I'm being 100% transparent, I'm worried about the U.S. economy. For starters, the U.S. national debt recently surpassed $35 trillion. I don't know where the breaking point is. But the na ...