The Plastic Advantage

I was at a Christmas party last night when I realized I couldn't find my coat check ticket.  I dumped my purse and still couldn't find the little pink ticket.  When I talked to the coat check woman, she said, "Can you identify the coat?"
Sure, it's a long, black wool coat.  I described the collar and buttons.  She still had about multiple coats that fit the description.  She asked, "Do you know the brand?"  I had to admit I owned the coat for so long I just didn't remember.
Then I remembered something unusual about my coat.  I said, "I have plastic bags in the pockets."  She said, "What?"  I replied, "We have a dog and I have plastic bags in the pockets." 
She laughed as she went through the pockets of the coats she thought were most likely mine.  She handed me the coat and said, "Well, that's the most unique way to describe a coat."
Score one for plastic bags.