It's fun to see our language through the eyes of English learners. There's so much weird stuff that we just take for granted and it's through the experiences of new learners that we become aware of these things.

Here's a fun one: "an apron" evolved from "a napron" because it's easier to say. "Napron" referred to something hanging around the nape of your neck.

Along those lines, "A whole nother thing" is a common form of spoken English, despite "nother" not being a word.