|Welcome to the Monastery|
They dance around the editor knowing exactly what they're looking for, exactly how they're going to fix the problem, and before you even understand what's wrong, they've already fixed it!
Hrm. Sounds to me like a description of a programmer who knows both the code base, and the editor.
In other words, know your tools, know the existing code.
Knowing the code you seem to have a handle on, and others have spoken on it as well. I'll offer this meditation on tools:
One danger of tools is that once you become proficient with a tool, you won't want to learn new tools - that way lies the scorched earth of the vi/emacs battlefields, and the endless holy wars of language advocacy. Be wise enough to see past those.
Of course, Perl is a tool too. :-)