Surely I can't say "I have to go to the bathroom?"!

I only have vague memories of first grade, which was also in Michigan. I remember our teacher had a big name, Miss Matelski. And I think she limped, had polio or something. I know I liked her. I can’t remember what grade it was when I faced the dilemma of how to ask the teacher if I could go to the bathroom. I thought that it would be awful to say the word “bathroom” out loud. So I tried to walk up and ask quietly, but the teacher made me stay in my desk and ask. When I did, she said to the whole class, “Any time you need to go to the restroom, you just ask.” And I thought, “Oh, restroom, that’s the word I should use.” I had never heard that word before.