Drive through insanity

So last night was my youngest daughters "tumbling and gym" recital.  We got to sit in a hot crowded auditorium for almost two hours to see her preform for 3 minutes.  It was a very big deal to her and she was very excited, so I was happy to sit and watch so she could have that experience.  After we finished with the recital, we let her choose where to get dinner.  She of course chose McDonald's.  Now I don't love it there but I don't hate it either.  We go and we order two kids meals and a meal for my oldest.  Then we order a couple chicken sandwiches and cheese burgers for myself and my wife.  It was kind of a big order I guess.  We get our order and pull out of the parking lot.  My wife is looking through the bag and sure enough they forgot the fries that came with the meal my oldest ordered.  How hard is it?  They have a list of the food that goes in the bag.  Why is it SO difficult to put everything in the bag?  I pull around the block go back into the restaurant and get the fries.  They were very nice and didn't question me, but I just don't see why it is so hard.  I have had this experience more than  I would like to admit.  Look at the list put the food in and away you go.  Not rocket science.  That is all