Perhaps I'm reacting poorly to the phrase "reinventing the wheel", which connotes to me that you've examined the existing solutions and found them lacking in some means. (In my experience, the people who claim that they have really haven't, not in any detail.) Perhaps I've misunderstood you.
I didn't mean "reinventing the wheel" that way, but given how loaded the phrase is, I suppose I knew I was asking for trouble. To clarify: I never intended to replace File::Find. I wanted to see if I understood some of what I had learned from Intermediate Perl and the first chapter of Higher Order Perl, and the way I tested my understanding was by selecting a subset of File::Find's functionality and trying to reproduce it - not because I thought I could do better, but as an exercise. My original post (far) overstated how well I succeeded at even that limited task, and I see that the title is misleading. But I'm glad that I provoked strong responses. I was curious to hear what other, more experienced monks thought of this as a learning exercise. As I've said a few times, I'm completely isolated as far as programming goes, so all the feedback has been very helpful.
In any case, I appreciate your responses; the comments about 'prior art' are especially helpful. Although I use plenty of modules for their functionality, I haven't made enough use of the actual source code as a teaching tool.