The only problem with don't answer a number unfamiliar to you is occasionally I've found it's been the fraud department of the bank trying to tell you they've blocked a suspicious transaction on your bank account (and thus the entire card/account, which is kind of useful if you don't actively monitor your bank account but also I hate that they can just do that).

But that is otherwise how the kids with phones and I operate XD (don't answer unknown numbers).

I remember the car accident one, have gotten it a couple of times.