You dont have to keep making pong all the time, but dont get ahead of yourself. If you set yourself a huge project, chances are you will never finish it, and then be left disappointed. If however, you work you way up, and complete everything, you have a real sense of accomplishment, and that you are getting somewhere.
Dont do any more pong, try a tetris game (also simple), then move onto some 2d platformers or something. Then you could think about 3d, and getting a really basic game happening (space shooter maybe). Just remember that games like Quake and Wolfenstein were made by many people with a lot of experience. You shouldnt expect to be able to recreate that by yourself with any degree of ease
Just trying to be helpful, and make sure you set your sights realistically for the near future