It wouldn't be very surprising if the vast majority of teens who do not know how to write a letter have parents who do not write letters themselves. That said,

It wouldn't be very surprising if the vast majority of teens who do not know how to write a letter have parents who do not write letters themselves. That said, it seems surprising to me that the topic of 'where does the mail come from and how does it get to where it is going' would have come up at least once in 18 years of childhood given that mail shows up at homes every day. When I was teaching middle school several years ago, my 6th grade students didn't know about long distance phone calls. I took it upon myself to give a basic explanation about phone calls, switchboards, and even things like 10-10-321.