Me at Walgreens drive through, like 13,724 times in the last 14 years I've/we've lived here. The same core staff has worked there the whole time basically, the pharmacists anyway, and Michelle, the pharmacist was at the drive through today. 

Me: "Hey Michelle! Picking up I think 3 for me, and the usual, you know, could you check if there's anything for Chad as long as I'm here"

Her: "Sure thing!" (smiles brightly and off she goes)

Her (coming back): "Just 3 for you today! Any questions? It sure is hot today!" (blahblahblah finishes transactions with small talk and smiles)

Me, now at home, realizing what I'd done: ohhhhhhhh...... 

((( thank you Michelle )))

Obviously, my brain still forgets that it happened sometimes.