btw this is from the bulbapedia article about the memory girl
"Pokémon received from events or transferred from a Generation V game won't have any memories of their original Trainer; the Memory Girl will say "The Pokémon seems to have a good memory, but it doesn't seem to be able to remember..." They may still make new memories with their current Trainer however. Pokémon who have a memory exclusive to Omega Ruby and Alpha Sapphire will also display this message in Pokémon X and Y; the memory will be displayed correctly if traded back to a copy of Pokémon Omega Ruby or Alpha Sapphire."
try it out with any event pokemon.