So it turns out I'm a goof (this is not surprising)

Bolding emphasis mine, which is what I'm responding to here. That's absolute hogwash. You are one of the most methodical, logical and practical thinkers here on Perlmonks, and I've felt that for what, two plus decades.

You hit, as you said, a de-facto situation of Rubber Duck Debugging. You're not the Maple Leafs... you're a Perl Hacker ;)

I know what it's like to have that "sigh, I'm an idiot" moment. Awesome feeling, isn't it!