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 :)