Disclaimer: I don't have a comp sci degree.
I've found having an understanding of the underlying theories supporting the tools (that includes languages and libraries) I use makes me use them better, understand their strengths, weaknesses, and how to improve them. It also helps me look at problems from various perspectives and see how other solutions may fit, including those that don't already have a tutorial or library.
I suspect that if you're an effective programmer, you're doing more than copying and pasting and growing in experience, and you're actually absorbing and apply more computer science than you realize.