You are wrong because I said so

Yesterday I gave a talk on endometriosis to my tutorial group because I was required to do so, but also because I am wise and inspirational and my Esteemed Colleagues always clamour for more like adorable little magpie hatchlings being doled out worms by a caring parent.  But the specialist who was marking us did not share their boundless enthusiasm.

Gruff specialist

You were incorrect when you said in your definition that endometriosis occurs outside the uterus.  It can also occur in the muscular wall of the uterus.

PTR

But that would be adenomyosis which is a different thing.

Gruff specialist

Adenomyosis is just a type of endometriosis.

PTR

But this is what it says in my primary source: "Endometriosis is defined as the presence of endometrial glands and stroma outside the endometrial cavity and uterine musculature".

Gruff specialist

You must understand that the people who write these things do so because they have nothing better to do.

Whereas the true authorities are so busy that they are able to drive out to Woop-Woop and spend all day falling asleep during student presentations and eating our cheese.  Aaaah, I see.