How to develop photographic memory (how to develop it in general), if yours is like an aquarium fish?

No way, photographic memory is a brain defect. And in fact, the owners of such memory say that this is more a disadvantage than an advantage.

The fact that it can be developed is just a myth that the speakers came up with to make money on it :)

To develop natural memory, try memorization technologies - https://ilgiz-sabirov.justclick.ru/CBEPX-zapominanie

I can't answer this question directly, because I myself have a memory, like an aquarium fish. Yesterday, for example, I put a jacket somewhere in the office - I still can't find it.

I'm not really sure that photographic memory can be developed. Therefore, since childhood, I had to work around the problem in this way - if you cannot remember something, figure out how to remember it. For example, I can't even remember a four-digit pincode. How do I do it? I come up with some simple formula to help me remember a set of numbers.

For example, 3279.32 is 2 to the power of 5. 5, 7, 9 are three consecutive odd numbers differing by 2, and 5 looks like an inverted two. So, we have reduced memorizing 4 numbers to one - two, and a few simple operations.

Apparently, that's why I became a mathematician, not a historian.

З.Ы. Do not try, this number will not match any of my cards.
З.З.Ы. As far as I remember ...