I always love on my first day:
"HEY DOOFUS YOUR NAME MUST BE RAZIR CUZ YOU EMO SLIT YOUR WRISTS HAHAHAHAHA"
"uh no. your pronoucing it wrong. here. [Writes down prounonciation]
Yeah.
Gold was out of stock. Back then when I didn't get the version I wanted: "NOOOOOOOOOOOOOOOOOOOOOOO MY LIFE IS A LIEEEEEEEE!" [Happened when I wanted Blue , Yellow (THEY DIDN'T HAVE IT AT ALL D: ) and Gold.]
Now: "Eh , oh well." (Happened with Pearl and Emerald (i had to get ruby instead :()