I did not want to know my blood type.
My mother had one of those highly sought blood types. The Red Cross would sometimes call when she was a little late for her donation. But she was rarely late; She had received someone else’s blood during an operation.
In some high school biology class, I had worked out that it was highly unlikely that I was anything but a standard O positive.
As long as I didn’t know there was always a small chance that I had special blood.
In the army, no one is special. They needed to know what to stamp on my dog tags.