One summer's day my wife and I journeyed to Pittsburgh, Pennsylvania, to attend a conference. We packed early in the morning and joined a colleague and his wife for breakfast. The other couple was also attending the Pittsburgh conference. After saying "goodbye" to our friends, we indicated that we would see them at the hotel in Pittsburgh. We were leaving directly from the breakfast while they were not leaving for another two or three hours, after they went home, packed, and took their children to the hotel. Diane and I pounded up to Pittsburgh, driving a few miles over the speed limit and stopping only for gas. When we arrived at the hotel, we carried our luggage from the car, and there to our amazement was the other couple by the swimming pool. "Where have you been?" he asked. "We've bee…