Getting to build things without skinned knuckles or solder smoke in your face... now that is a rush! And if you are not happy with it, you get to tear it down and build it back up better. It costs nothing but your time and imagination. Importantly, you get to build, to solve problems, to engineer, to visualize, to create and be creative. (Ok, maybe musicians have even more fun, but alas I wasn't wired for music. :-)