Of course, the answer to that question is obviously "too many." This sort of tragedy is completely avoidable, and should never, ever happen. Not even once.
Let's say that you've gotten the COVID-19 vaccine, and your best friend hasn't. Are you more of a "live and let live" sort of person who is cool with others making their own decisions while you make yours, or do you have to end the friendship?
You'd think that after stealing a car, you'd know better than to stop for a minute to chat with the police about the best way to get where you're going. You'd think that, and you'd be quite wrong.
In the interests of full disclosure, I'm forced to admit an uncomfortable truth. I really don't hate mayonnaise. I don't love it, either. I'm okay with it. Is that alright?