You will not know who Goku is unless you watch the Dragon Ball Z series. It was highly popular especially before when a lot of people watched it because they loved the stories and the adventures that Goku and the rest of the gang encounter each time. Aside from their fun adventures that are fun, they are also well known because of their various things that they can teach to the public. They probably taught you how to work in a team and it is likely that you have also become loyal because of them. Want to show your loyalty now? Do that by placing them as your desktop background.