Cn u rely get amnesia frm bumpng ur hed and is there a specific part of ur hed tht wen u bump it u get amnesia?

Most people with permanent amnesia have anteriorgrade amnesia. They can remember what happened five years ago but don't remember the last five minutes. Often the pathway memories take to become permanent is so disrupted that they remember nothing after their injury and are forever mentally frozen at that point in time. They're rather sad cases.

Retrograde amnesia is what you see in movies. You remember what's happened since the accident but little or nothing before that time. The older the memory the more likely it is to survive.

Wikipedia says this is caused by damage to the hippocampus or the frontal lobes, which makes sense given what those structures do. The hippocampus is deep inside the brain towards the bottom and unlikely to be injured. The frontal lobes can be injured by striking your forehead, or a whiplash type injury where your brain is crushed against the front of your skull.

Will being hit again help? No. Absolutely not.

Yes you can. Amnesia occurs when damage is done to the hippocampus