I was in a similar boat yesterday.
My friend wanted help with a simple job of taking a door off, planing the bottom and putting the door back on...
Took the door off no problem, rested it on a chair to plane it. There was a peice of wood stuck to the bottom and the nearest thing to hand was a penknife. (seemed a good idea at the time).
Trying to lever the peice of wood off, door slips, knife slips onto my finger, door falls onto knife, knife cuts cleanly, quickly and deeply into my finger.
Rinse finger under the tap to see the cut is about 4mm deep passed all layers of skin into the flesh underneath.
Next thing I know friend is standing over me asking if I was ok.
Trip to A&E and knew i was in for stiches when a doctor exclaims "Oh my God! that is deep". 4 stiches later and a big white condom where my finger should be...
Though all of this my finger has never hurt once but a paper cut hurts for days :-)
Ross