A girl I've dated for a while worked as photographer for live events reportage, clocking even thousand shots for event and saving at least a hundred of them for the job, and she told me rather often she was being later contacted by the client, or someone of his entourage, or even some other person from the public, months past the event and asking if she could send them e.g. "that picture where I'm standing with that friend of mine wearing a white shirt...", and all that of course without even being able to tell her the actual date of the event.