I have a finger that the tip doesn't bleed. It was over 20 years before it got any feeling back in it.I learned very quickly to respect very sharp knives when I bought a set of Henckels Twin Four star knives. The very first time I used them, I was trying that speed chopping thing with my bird's veggies.
I looked away for a second and took the tip of my left thumb off clean. It took a long time to grow back to normal looking, however, I still have very little tactile sensation in that tip.
That wasn't a knife accident but a cousin and a door.