The important thing to remember is that at the beginning, all these ideas look equally bad. When I first got the idea to use (?{...}) to invoke a callback in a regex debugger, it seemed absurd, a weird hack of a little-used feature to do something that nobody was sure was worth doing in the first place.
I think if I had been asked on day 1 to estimate the maximum possible value of this idea, I would have supposed it might be good for an April Fool's prank of some sort. But it turned out, after we put in the proverbial 99% perspiration, that it was a workable idea, and probably even has some commercial value.
So lesson number one is that most non-obvious ideas look pretty strange the first time you see them, and you shouldn't send them away even if they have horns and snaggle teeth.