Sometimes adrenaline kicks in and you don't even know things like that.
A buddy I play basketball with had a stick sticking out of his head after a branch fell on him and didn't notice until his wife saw it.
While shooting my rifle at a range years ago, the barrel of the gun slipped off my shoulder, and the scope nailed me right above the eye. I didn't notice anything until blood started pouring out of my eye about 60 seconds later. Took about 10 stitches to fix'er up