Really? I can't empathize with that. Every answer raises more questions.
Mr. Kreider makes an interesting point about information before the internet, but I don't think the internet has killed mystery, and definitely not obscurity. This essay seems a bit of a nostalgic reflex to me. He needn't worry about kids. I'm sure if he asked some, they'd overwhelm him with obscure stuff he had never heard about.
The quote: "Learning how to transform mere ignorance into mystery, simple not knowing into wonder, is a useful skill". bothers me a bit. We have plenty of ignorance. We are swimming in our own ignorance. I know nothing compared to what could be known. IMHO ignorance is not 'mere' or endangered. -It's most of what we've got.