Misspellings and misuses of words in books drive me crazy and always have. The absolute worst I've ever seen, though,
goes way beyond these. There is a doctor who used to write a column for Discover magazine. She wrote a book called
"Other Peoples' Children". (I think. She's a pediatrician.) She surely must have written parts of it at different times, because one chapter--only--in the middle of the book was written in the first person, with no explanation. All of the others were in the third person! Where on earth was her editor??