I really liked to do this! I used to be able to use the ´Memory palace`it was really fun to do for some reason haha. My best time was 15minutes to remember the whole sequence of a deck of cards.
The trick was to create a ´palace`in your mind. In my case it was my own home. And each room was a place where you would put objects that do something. So in that way you create a story.
If you had made the story, then just simply start at the beginning of your home and imagine walking through your palace and each room you enter you remember bits of the story.
In the case with my cards. Each object represented a certain card. so I could name the whole deck within minutes. The fun part was. People were super impressed by it, while it was just a memory trick wich you can learn within hours of active practice.
Fun post I´d like to see more!
Yeah, I went to many competitions and I have seen people doing it under 30 seconds. My own record was 78s many years ago.