Mrs. Shlobovitz will know you. She's 83 and seeks you out for the 18 seconds of interaction she has (with anyone) each week. You're famous to her. Unless you're gone, in which case she goes to Bob in aisle 2. Or if he's gone, she goes to Moishe in aisle 7.
The important thing is that you are famous…to her. Or…well, she knows who you are, more or less, for 18 seconds. Beep.