Grossman goes on and on with examples of bayonet fights it's a very interesting chapter. Then he arrives to knives. Killing with a knife in hand is different then killing with a bayonet on the end of the rifle.
Many knife kills appear to be of the commando nature, in which someone slips up on a victim and kills him from behind. These kills, like all kills from behind, are less traumatic than a kill from the front, since the face and all its messages and contortions are not seen. But what is felt are the bucking and shuddering of the victim's body and the warm sticky blood gushing out, and what is heard is the the final breath hissing out.
Special forces got training on how to kill silently and efficiently with a knife or dagger in such situation.
Holmes tells us that the French in World War II preferred knives and daggers for close-in work, but Keegan's findings of the singular absence of such wounds would indicate that few of these knives were ever used. Indeed, narratives of incidents in which individuals used a knife in modern combat are extremely rare, and knife kills other than the silencing of sentries from behind are almost unheard of.