Go to a clothing or grocery store every day for a month. Dressed the same. Always go to the same section of the store and buy the same thing. (Perhaps something you wouldn't buy everyday, like a movie or lunchables.) Go to the same checkout counter. After you're done purchasing ask for the same amount of cash back. And specify what you want exactly - like one five and five ones or two tens. Then watch as recognition and then confusion unfolds. I'm curious to see what would happen.
Well. Sleepytime is nigh. Nigh!
And I've reached my loopy stage of staying awake so I'm going to stop typing before I embarrass myself.