Technical writing is one of those jobs in which you're constantly learning. New tools, new techniques, new methodologies. No one knows it all. That's especially true for the new technical communicator. If you've graduated from a writing and rhetoric course or a technical writing course, you have a pretty good grounding in craft. But you're really only at the base of the mountain. There's still a lot to learn, and if you keep your eyes and ears and mind open then you can quickly pick up what you need to know.