The weirdest “likelihood” conversation I ever had, the putative team lead didn’t want to change priorities to fix a bug because, “how often does that happen?”

My reply was, “it happens to every user, the first time they use the app.” And then something about how frequency has nothing to do with it. Every single user was going to encounter this bug. Even if they only used the app once.

I already had a toolbox full of conversations about how bad we are at statistics, but that one opened up a whole new avenue of things to worry about. One that was reinforced by later articles about the uselessness of p95 stats - particularly where 3% of your users are experiencing 100% outage.

But the one that is more apropos to the linked question, vs HN in general, is how people are bad at calculating the probability that “nothing bad happens” when there are fifty low probability things that can go wrong. Especially as the number of opportunities go up.

And the way that, if we do something risky and nothing bad happens, we estimate down the probability of future calamity instead of counting ourselves lucky and backing away.