The patterns you design with Fractal Noise go on forever in all directions.
Try adjusting (or animating) the Offset Turbulence property to roam in the fractal landscape.
You might also enjoy animating the Evolution property, which will make your funky background morph into other funky backgrounds.
If you animate Evolution to rotate completely around the circle (and as long as you don't animate any other property), you will create a seamless loop