Never been knocked, nor have I ever knocked some one out.
When I was 15 I got sucker punched by a guy who had a roll of quarters in his hand. Crushed my face, but to this day it is legend that I never went down and freaked out and nearly ripped the dudes ear off. I don't remember anything for about 5 hours. I half remember being in the hospital and doctor saying he couldn't believe that hit never killed me. I had a severe concussion, a 2 inch gash on the side of my nose, my cheekbone was dislocated, my nose was crushed and lying on the side of my face, 4 teeth knocked loose, my eyes were swollen shut the next day, and both of my lips were split. My friends who knew me all my life couldn't hardly recognize me the next day.
I had to have reconstructive surgery 2.5 weeks later. Nose is still fucked up.