I've encountered this expression in DBZ Abridged, and I haven't encountered it anywhere else, save for occasional use on some forums. The context is the following:
"For God's sake, I bet even your father can do it--he's just not stupid enough to try! And as we've seen today, that threshold is vast."
I'm infering from this that the speaker is implying that the addressee's father is indeed very stupid, making the addressee's stupidity even more appalling. But I have no idea why the word "threshold" is used here, and how can one be vast - considering a threshold is usually a singular point or line, not something wide. Any help?