It's so easy to tell lies and have people believe them. That's a big human flaw it seems :-/ that needs to be corrected, governments and corporations get away with public opinion manipulation way too easily. >:(
It's a matter of speech, not a concrete measurement. I'd liken the speed to a "compiled" version of the problem in your mind; if you've done it before, it's easier to apply it now, rather than to start from the beginning to understand the problem.