You may have just come across one of those terrible teachers. I had a few over the years that just passed on completely incorrect knowledge. Take for example "cuckoo spit" that my teacher in primrary school insisted was just sap from the plant. I tried to argue it was made by a bug eating the plant and that my father, a professor of botany at a red brick university, had told me this. Other children wouldn't have it, teacher was right, and so goes 25 young minds out the door with the wrong information.

My very first job before deciding to go into the law was working a teacher, the power you have is staggering, perhaps less so know with the ability for children to fact check in an instant, but back then the word of the teacher was the single source of truth.