What they get wrong is that thorn is not entirely extinct—it’s quite common in Icelandic (along with its voiced counterpart eth or ð), which is similar to Old Norse.
I’ve written about K. It has a really interesting backstory. You might want to try it.
Truman Capote claimed he couldn’t recite the alphabet so an interviewer (Laurence Grobel) tested him. Capote tried, screwed up, tried again, screwed up again, so then just gave up.
