Reasonable optimism serves us well, lowering stress and anxiety. But studies suggest that people can be foolishly optimistic to the point they shut out negative information. (Example: the teenage girl who thinks she can have unprotected sex without consequences, the person who doesn't save for retirement because "something always works out." Dr. Veronica looks at the line between a bright outlook and foolhardiness with experts on the pursuit of happiness. Russell Cook co-hosts.