Perhaps what you're experiencing is the Dunning-Kruger effect: that people who are unskilled frequently rank themselves as more competent than people who actually are skilled.
Hmm.. perhaps. Still it seems a wildly bold to overestimate yourself by such a large amount. We're talking about the absolute basics here. I mean, I look at job postings and come away depressed after realizing I don't recognize half the stuff they want 5+ years experience in. So what does for-loop-not-knowing guy think we he sees the same requirements?
I dunno. I just think it's strange that they even get to the interview stage.