There are text and video here:
There might be more on the Internet about this kind of thing, but there appears to be few people, there might even be a TV series about such a person soon.
I have not read or seen all of the stuff, but it appears as if some of them might remember more than the others and maybe, but I am not sure, maybe none of them remembers everything, just a lot or most everything, but as I only started to read the stuff, I might be wrong about that.
I myself don't have a good enough memory and maybe I even have a not so good one, but I do seem to have some memories of when maybe I was about 4 or 5 years old and most of those few memories are "clear" enough, so my memory seems to start and go back to when I was about 4 to 5 years old, but even so I don't have a good memory or a good enough memory, that is my own opinion.
I do seem to remember some things and forget others, I guess that it might have to do with attention and interest.
Why remember that which you don't want and or need to?
There is too much memory "trash", Why would anybody want to remember everything?
I guess that some people might have no choice about it.
It does appear as if we all have ALL the memories there, just like those people, but unlike them, we can't get to most of them and not with the detail that these people can.
They also have complete sequential memory while we have isolated broken up memories, but all the complete memories are probably there on all or most of us, we just can't get to them.
I just finished reading the stuff, I am also left handed, but thru the years have learned to also use my right hand a lot for many things, but I still favor my left hand and even write with it, I type with both of them and do many other things with both of them, but my left hand is stronger and also can do more detailed and smaller stuff with it and have a few more things in common with them, but it was more like so years ago, most of it, except for the very good memory.