Yes, this can happen.
cause it was a ACCIDENT should you lose a lot of blood during a accident?
No
You can lose your memory from becoming old or from losing to much white brain cells.
I have a vivid memory of my grandmother's garden from when I was a child.
Uhm...no
No
No.
If the accident is bad enough, you might lose your baby. You should get a medical check-up.
Yes, it is possible.
Their memory.
YES
People start to lose their memory when they get old like 50 years old, and that is called old-timer's disease.