The Exchange -

Customer: "Do you have that self help book"
Me: "Sorry, which self help book? Do you know the title? Or author?"
Customer: "No, It's that self help book"
Me:"umm... okay, well we have a whole section of self help books. Did you see it on Oprah by any chance?"
Customer: "No"
Me:"Okay, what type of self help book is it?"
Customer: "Self Help"
Me:"I understand that, but there are many different subjects that fall under that category. Did it seem generally inspirational or more specialized, like dealing with grief for instance?"
Customer: "Self Help"
Me:"Umm...okay - here's the self help section. It might be best if you browse and see if you can see it."

I have no idea if the lady found what she was looking for; I went on break after a few minutes. I hope she found "the" self help book.