Memory issues

I’ve been told that autistic people have fantastic memories.  A few people on the spectrum are like walking encyclopaedias.  I am not like this.  I have always had a very poor memory.  I had surgery on my wrist years ago and cannot remember which wrist it was.  There are people I went to school with that remember me, I don’t remember them.  This was back in high school.  People will tell me something at work and have to repeat it several times and I still won’t remember it. I don’t remember hardly any of my birthdays, chunks of my life are gone.  It has always been like this.  I feel like I’m broken.  Sounds bother me, smells bother me, people bother me.  I don’t know what purpose I serve here since I don’t find enjoyment in much.  If I had a great memory, I would love to go back to university to study.  I went to college for nursing and it was such a struggle to pass all the courses.  Is anyone else like this. I don’t know what to do to improve my memory.  I feel like I am falling apart.