There we were, lined up with all the other runners at the start of the marathon. Pretty keyed up, in good shape, and we're off with the start! Running well, starting to get warmed up, working through the adrenaline buzz to settle in to the pace. At the quarter mile mark, a gap appears in the front runners, and we surge into the lead. Then BAM! Someone steps on our heel, trips us, and all of a sudden we are on the ground while the rest of the herd goes surging by. We stagger up, trying to find a rhythm again, while more runners pass us up.