I recommend searching the web for "tail recursion" and "recursion vs. iteration" to see just how similar recursion and iterative loops really are. If you have time, get your hands on The Little Lisper or its descendent The Little Schemer and work through the whole thing including the exercises. It's another language, sure, but both are very influential languages and the books are really good at imparting some recursion wisdom. The Little Schemer even has sequels The Seasoned Schemer and The Reasoned Schemer which I'm told are also very good.