But it's free

I was at the grocery store this morning and the strangest thing happened. At the checkout line 2 shoppers were in front of me. The man being checked out bought a package of gum. Clerk said the gum was buy 1 get 1 free, and did he want to grab another pack. He said no. So the clerk asked if he wanted her to get him another pack. Again he said no. So the clerk asked him if he wanted the second pack, and again he said no. I was dumbfounded as was the clerk and the lady standing between me and the man. So the lady said that her daughter liked that kind of gum and would he just take the free pack and give it to her. So he did and she got the free gum. I totally don't understand it. It is not like the gum will go bad in a few days. I never leave my FREE stuff at the store. Even if I don't need it I know enough people that someone can you use. To me it is like going to the store buying a carton of ice cream and them just walking out without. Go figure.