Good ones only engage when you don’t act fast enough. They’ll also press the brake pedal harder if it thinks you aren’t pressing hard enough fast enough.

Ours only engages when it is truly justified. It has yet to flip its shit incorrectly. It’s adaptive cruise control on the other hand will sometimes freak out about cars in adjacent lanes and slow down more than it should.

Our Volvo V40 saved our butt once on the highway. Late at night, cars piling up all of a sudden in front of us. The car slammed the brakes and stopped us a few meters away from the car in front :-)

I also have a V40 and have also had an experience exactly like that on a motorway - bright red lights flashed at the bottom of the windscreen along to a warning sound and the autonomous braking kicked in and stopped me from hitting the car in front. Excellent system.

When I was a kid - this was quite a few years ago - I had some older relatives who refused to wear a seat belt. Being somewhat of a brat, I asked them why. They answered like this:

"If I get in a wreck, I don't want to be trapped in the car. I want to be thrown clear!"

This might be just me, but I don't think it's bratty to question truly idiotic behavior.

I think it's obnoxious to call people "truly idiotic" if you would not apply the phrase to everyone who takes "unnecessary" risks. I am conditioned from childhood to wear a seatbelt in a car, but I also have owned a motorcycle in the past, and currently own a pre-airbag car (which I assume also lacks more subtle features like modern crumple zones and high strength steel, etc.). What makes one risk reasonable and another not?