All Genealogists were once beginners... and if they keep branching into new families and locales, they in a sense will always be beginners. I've been doing genealogical research for 15 years (rather amateurishly the first several years), but as I branch into new areas, I have to learn new tricks. I'm pretty experienced in 19th-century Midwest research, as well as Dutch and Swedish research. But, now that I am pushing some lines back to places like Virginia and Ireland, I feel like a beginner again. Guess what? It's a good feeling, because it's fun to learn.
The good news is that the basic research methods we learn are transferrable to new areas. Yes, we have to learn about new kinds of records, and even tackle new languages, but the basics of evaluating sources, correlating data and drawing reasoned conclusions is largely the same, regardless of where our ancestors came from. This is one reason I urge people doing English or German or Norwegian research to join a local or state genealogy society. When you go to a conference, don't just go to the sessions on your nationality, take in the sessions dealing with research methods or American genealogy, because you will learn skills that will help you with your ethnic research.