While testifying as an expert witness in a trial one day, Henry Rowland was asked during cross-examination what qualified him to serve as such a witness. "I am," the professor replied, "the greatest living expert on the subject under discussion."
Some time later a friend, well aware of Rowland's usual modest and unassuming manner, expressed his surprise at this uncharacteristically grandiose remark. "Well, what did you expect me to do?" Rowland asked. "I was under oath!"
Sources
Isaac Asimov, Treasury of Humor; Isaac Asimov`s Book of Facts