Anyone who watched the McCain-Obama debate on Wednesday, or heard about it's aftermath, will know about Joe the Plumber. John McCain told a story about Joe Wurzelbacher, an Ohio plumber and handyman who confronted Obama at a rally last weekend. The point of the story was that Joe would pay more taxes under the Obama plan, according to McCain, and therefore Obama's plan to "spread the wealth around" was flawed. Joe clocked up several more name-checks from each candidate during the remainder of the debate.
Naturally, the news media were keen to track down Joe and find out his story. Unfortunately for McCain, it turned out that Joe is a tax defaulter, with no plumbers' licence, who earns less than $40,000 a year, so would be better of under Obama's proposals. Oops.
If you are going to use a personal story - whether about yourself or someone else - make sure that you get the facts right. Otherwise you risk looking foolish, since the truth will nearly always emerge. It doesn't matter if you are running for president or talking to a small audience of potential customers, you need to do your research, and tell the truth.