m&ms

We stopped into Ace Hardware this morning.  Pulling into the parking lot, Molly inquired about m&ms.  On our last visit, I had told her that we would get popcorn.  They have free popcorn all day every day, except for our last visit (of course) when I had promised it to Molly.  So, I let her get some m&ms from a gum ball machine instead.  Getting out of the car this morning, she insisted on m&ms.  I told her that we were only going to get popcorn.  Again, getting a cart in the store, she saw the candy machines and asked for m&ms.  In response I handed her a bag of popcorn!  We browsed for a few minutes while she munched.  After we paid and were returning our cart she told me, "I changed my mind."  What kid changes her mind about m&ms?  How did I get so lucky for no toddler emotions to erupt during this whole exchange?