Afaik no one has ever been proven to have photographic memory (e.g. being able to remember random dots on an image is used as a test, if memory serves right). So for the most part it is just a nice little character trait for movies and the likes.

I noticed that a lot of people I know are significantly better at remembering some things, in this case numbers, but worse at other parts (e.g. conversations). So oftentimes its also a matter of what exactly you are good and bad at remembering.

Depending on the context, it also comes with experience. Think of games like chess, poker, etc. Experienced players are often able to replay an entire match, which in large part comes from their experience and the context of the many games they’ve played. If you met the same people in their first few matches, that ability would probably have been a lot less developed (if that makes sense).

No scientific backing on these statements, it's just based on my personal experience and impressions.