I've worked with a lot of very good database people that were pre courses (started our careers in the early 80's) so all self taught. They would definitely have some troubles explaining normalization in academic terms and would only use experiences. One of them had worked with Oracle from v4.0 to v8.0 and could not tell you what third normal form was yet always designed and built systems that worked and met normalization rules. He failed an interview because he could not name and academically explain 1st through 5th normal form. Yet he was the go to person for any of our DB designs as his systems always worked, worked fast and had no, I repeat no, data issues.
So I got him to read https://www.amazon.com/Manga-Guide-Databases-Mana-Takahashi/dp/1593271905 and with the information in the book he can now academically explain them and is now a senior database architect with a large Australian bank. Still has no formal IT education not certificates.

Frustrating that some recruiters believe that formal education and the ability to regurgitate learning is more important than experience and proof of value.