Not my first memory.
When I was eight years old, I was wondering how long I could remember something. So I started an experiment. I decided to remember what I did that day for as long as possible. Every evening when I was in bed I would try to remember it. That was 30 years ago and I still remember that that day I went playing with a friend and we tried to make a swimming pool in his parents backyard and we played with some wild cats.
I hope I can keep the experiment going until Iβm at least 90+