Our world is built on a foundation of sand. You have seen the insecurities with individual programs. Consider that these programs, in turn, are pressed together into complex systems. Humanity tries its best, but the parts of systems do not fit perfectly, and gaps of insecurity abound within the seams. Hackers know the art of sneaking through these gaps, and now, you have reached the point of your journey where you shall develop this art as well. Push through, and join us on the other side.