My brother had his appendix out when he was about 13. Five or six years later, he confessed to me that he had made it all up to get out of doing some homework. He made all the right noises at the doctor’s surgery, who sent him to the hospital, where he fooled them again.
After the operation, he says the surgeon spoke to him and mentioned it was odd because there wasn’t any inflammation. I am amazed that in the days before the internet, he knew where his appendix should be.