This is the best explanation I've seen.
Here's the link to the whole article: http://www.newyorker.com/reporting/2008/07/28/080728fa_fact_vandoren
Once I went to use the bathroom in the lobby of my office, saw someone waiting to use it, who I recognized, said hello, and then realized it was Kristen Schaal and I knew her from TV, not real life. Then I had to wait with her for five minutes while she waited for her friend to be done. I think I said something brilliant like "ummm waiting for the bathroom."