I have managed to do pretty decent work despite my lack of theoretical knowledge, and I have put a couple of green CS grads to shame.
That reminds me of the time a CS intern came to work for the summer at a company I was at. He was very, very bright, knew several programming languages and was pretty handy at server administration. When the intern left, he told his father (friends with our boss) that he walked into our company convinced that he knew everything there was to know about programming and was just in college to get the degree. He left us absolutely amazed at what we could do and he was eager to intern with us the next summer. Only one person in our department had a CS degree. The rest of us taught ourselves.