... punches can cause memory loss?
A groggy boxer might have difficulties remembering his own name right after taking a hard blow to his head. But what happens, when a blow sends the brain down for a count?
It is quite normal that one's memory disappears for a period of time after a hard blow to the head. Memory loss can regard the past, so it is suddenly impossible to remember one’s own name, or regard the future, so it is impossible to store new, permanent memories.
Often, the memory returns within a few minutes, but in severe cases, it could take several days. Even during brief periods of memory loss, the brain can still remember many things. The older the memories are, the better they "stick" to the brain, and so, in spite of memory loss, it is easier to remember what happened 10 years ago than last week.
Usually, a blow to the head influences the episodic memory the most, which stores our personal experiences, covering anything from childhood memories to something we experienced earlier in the same day.