Whenever I cross a crosswalk I think about how easy it would be to run me over. Defense is far harder than offense, and we rely on consequences to disincentivize bad behavior. That works only in so much as someone isn't insane, and isn't willing to die themselves in order to kill you (e.g. a suicide bomber). High value targets have to avoid being seen in public.
Yeah, it's quite a journey from being a careless kid to actually thinking about stuff like that and I'm not even talking about targeted attacks. Just not to walk near fast cars or generally defensive driving etc. And sometimes also https://www.youtube.com/watch?v=8u-XIjXS98Q