(b) this is totally anecdotal, but as someone who has been teaching computer programming to adults for ~20yrs or so, the biggest obstacle that students face is not that the material is difficult (even when it *is* difficult), but that students are *culturally predisposed to a belief that they're not smart enough to program*, which acts as a permission structure for giving up. (this is peculiar, because no one having trouble in a knitting class thinks "i guess i'm not smart enough to knit")