As structural engineer Jan Vacca stopped in her office to grab coats and bags before heading to a jobsite in Philadelphia, she apologized for the clutter to graduate student Megan A. ToumaniosVacca's "shadow for a day." Clutter aside, the eye-catcher in the office that morning was the desk wall, which is papered with pithy sayings. "Angry people do not listen." "The more incompetent people are, the more competent they believe they are." "A fool flatters himself; a wise woman flatters the fool." Vacca's favorite quote, despite no mention of women, is Abraham Lincoln's: "Nearly all men can stand adversity, but if you want to test a man's character, give him power." The many postings, including good-behavior lists, are like mantras. "They are a comfort to me and they reground me," says Vacca, a vice president of The Harman Group Inc., King of Prussia, Pa. On March 27, Vacca offered advice to Toumanios, a future structural engineer graduating from Lehigh University. "Don't be afraid to ask questions or make mistakes," Vacca said. "That's how we learn."