By a 'knife hole', do you mean a stab wound?
Stabbing wounds often don't hurt at all when you receive them. Not in a sharp way anyway. More of a thumping sensation. Often people with stab wounds will die, not realising that they have been stabbed.
It is afterwards that pain occurs, and especially if any kind of infection is introduced through a dirty knife blade. It can even cause sepsis, which will, again, kill you.
If the wound remains clean and is sutured, there will be pain associated with the swelling that healing causes. Generally it doesn't hurt too much as long as, as you rightly say, you don't touch the wound.