I majored in English in college and took electives in Linguistics because I've always been fascinated by language. I also studied Latin, German and French in school and later became fluent in American Sign Language. I'm the author of five books and my work has been published in lots of anthologies and periodicals so the information I learned about our language has been useful to me for the most part.
But here's one thing I don't understand: why does anyone care about the difference between a metaphor and a simile?
Yes, I had to learn the definitions in school to pass tests, but in all my years as a writer and reader I've never needed to know that information.
Sometimes I use and read comparisons using the words, like, or as, and sometimes I use and read comparisons that don't use those words.
The meaning is clear either way.
Lots of things - maybe even most things - I learned about grammar in school are useful to know, but the difference between a metaphor and a simile is one thing I consider a waste of time to teach.