Don't worry, I'm... not entirely sure how to explain it. I'll try again.
Look at this continent. I'll describe it as a "T" shaped lump. The lower branch of this, a long thick peninsula, is always roughly the same width throughout. When one coast curves west or east, the other coast tends to follow it in the same direction and even same angle. Nature is rarely so symmetrical.
Look at Earth. Are any of the continents a uniform width in any one area? You can make an argument for Australia, I guess, but it's offset by the Indonesian islands in the north. But otherwise, South America tapers off to the south, North America is like a giant triangle with some water intruding in the middle, Europe looks like God had fun, Asia is like a firework, and Africa is magnificently offset. They're even pretty basic shapes overall in some cases, but they are never quite symmetrical. And the basic shapes have some interesting oddities: contrast Indochina with India. Look at the Hudson.
Right, done rhapsodizing for the moment. Is that clearer?