Why do people say they have photographic memory? When it's not possible?

Think, photographs were only invented in the 1930s. How did people memorize things before that? Humans simply can't evolve that quickly. Either photographs predate the classic, modern homo sapien, or everyone is lying and they are just guessing their memories. Answer?

Edit: thanks everyone, i think this is half-solved. Photographs are actually older because real pictures include the term photograph. Still not sold on how we can "invent" better memory but maybe some mysteries must remain just that. Thx everyone