This Could Never Happen Right? 10 Points?

I'm scaring myself with a really ridiculous theory. You see, I lost my Japanese textbook in the first semester . it wasn't used often and we never worked from it so I was OK. Then we had to turn our boks in and my teacher knew I couldn't find mine. It's summer nao and I haven't gotten a bill for the 40 dollar book. I made the teacher a card a week before school ended and had all his classes sign it, he didn't know about it. I gave it to the teacher who has his room. My teacher never said anything about it. I'm afraid that my teacher found out I sent the card and paid for my book because of it! I know it's really ridiculous so could you all just please reassure me of that? I just can't convince myself.