You don't remember your car accident. The police officers tell you what they think happened, and your dash cam even shows the moment of impact. It's all strange to you, as if you're seeing it for the first time. You remember getting in your car and starting the engine, but that's it.
Is this normal? What happened to make you forget such an important event?
First of all, it is common for memories to fail after traumatic events. You're not alone in this, and doctors probably don't feel that surprised that it happened. It's a common outcome, especially if you suffered a serious head or brain injury.
Part of the reason is simply that your brain tries to make sure you survive the incident. It increases activities that might help you get away from danger with your life. To do that, though, it may have to stop making memories to devote focus to the things you need most.
Your body also sees a jolt of adrenaline and noradrenaline in a time of crisis. The noradrenaline can "destroy" your ability to create memories and store them for later access.
Again, this is just your body focusing on what matters. If you die, storing a memory makes no difference. Your body switches into survival mode at all costs. One of those costs may be your memories of the event itself.
Just because you do not remember the incident does not mean you don't have a legal right to compensation for your injuries. Make sure you know what steps to take.