People often joke that in order to understand recursion, you must first understand recursion. This is funny as far as it goes, but it illustrates a common misunderstanding. (I’m not saying the people who make the joke don’t understand what they’re doing. They probably do, and are having a little fun with the people who do not.)
Novices often think that recursion means solving a problem in terms of itself, which sounds like an infinite regress. And it might be. But an important qualifier is missing in this description. Recursion is about solving a problem in terms of smaller versions of itself. The process ends because the problems get smaller until the process reaches some problem small enough to be solved directly.
It would be more accurate, but less humorous, to say that in order to have a good understanding of recursion, you must first have a rough understanding of recursion.
Related post: The secret to understanding recursion