18th edition = 17th edition? At least for Dr.M

We met Dr. M, our gynae teacher on Mon. During the class, she saw my ' gynecology by 10 teachers 18th edition' textbook and wanted to borrow it to make photocopy and would return to me on Sat. Without hesitation, i said ok. Guess what. Today she came in , bringing an older edition(17th edition) and started showing and telling me both books are the same actually, just that the publisher wanted to make money by changing some words and colour and then republished the book as newer edition.And she wanted to exchange for a newer edtion with an older edition. What the heck! Just for your info, 17th edition and 18th edition of that book were printed in year 2000 and 2008 respectively. Though i never compared both books before, i personally feel there should be changes, e.g the way of managing and treating a particular disorder. And she kept on insisting that such small changes aren't needed by students, only needed by teachers. And she kept on asking whose book is that,as i previously told her that book belongs to my friend. And she demanded me to tell her who's that.Haih..Seems that i have to create a good story to /not to exchange the book. You will never know what will happen if you don't. Anyway, an advice to all students, don't bring your English Gynae textbook to class in case you have Dr.M as your teacher!