And even if you haven't killed them outright, they can have permanent disabilities.

If you, or someone you know, gets knocked out, or experiences other symptoms of a central nervous system trauma after a hit to the head, please seek medical care immediately. It's not one those "take two aspirin and let's see how it goes in the morning" kinda things.

I'm just one person, but during my life I've seen this multiple times. I will refrain from boring you, and doxxing myself, by telling my anecdotes. Suffice it to say that I have known people who would have been dead if they hadn't gone to work with a "bad hangover", or ended up with narcolepsy or chronic encephalopathy. And that was separate people BTW.