Think of identity as a flame. It grows by consuming new ideas, labels, and ideals. Some of these things burn longer than others. Some are just fads and go up in a puff of smoke. Some stay long enough to make a difference. And some are hardy, and burn with us for the rest of our lives. Even though they all become vapour in the end, every one of them leaves its mark on us - a mark of soot and ash, of things gone but still remembered.