Natural design is everywhere, especially in the unique grain of wood. Along with showing how old a tree was when it was harvested, it gives every board character. No tree's markings are the same as another's, which gives an authenticity to every wood working project ever done in the world, ever.
Having the grain of your wood wrap around your project helps give it a planned, finished look. Even when you are working with rough cut construction lumber. All you have to do is cut a wedge out of your board at 45's and it naturally keeps that edge's grain continuous on the outer edge. (try this with other materials too)
So, next time you have a project with a board that 'wraps' around a corner, instead of just flipping your board to save an extra cut, plan to use the same side of your board all the way around. It's only about an extra 2 inches per board.