Being a Linux geek type, I'd look at cooking first, my guess would be you can't even put together a simple meal, much less bake yourself a loaf of bread, something that would be required to be considered "literate" at food preparation.
Now, there's a deeply entrenched stereotype for you. Living alone, I don't do much cooking (or, hence, eating), but when I can ass myself into it, I do make a rather nice chicken in white wine of my own, or *find and follow a recipe* (!)
I'd agree that the normal user shouldn't normally see a cli interface, but failing to be able to copy and paste a few commands into one, with amble description of the process, progress and expected results, I'd take on your comparison, and say that's equivalent to looking in your Home Eq book, looking at the pot, the faucet, the stove, the eggs and then order out.
Granted, people as a whole have been cooking for a longer time than they have been using computers, but I will say that it's the fear, more than the required intellect, that's the problem. It still is a problem, though :-(