Ok, sorry if I'm asking a really dumb question here - but why is it so important to carry ID with you? I mean, I can see that it's important to carry details about allergies or illnesses you have so that you get the right medical treatment, but isn't ID and contact info more in the category of "handy to contact family afterwards?"

Or is this important for insurance purposes? We have free healthcare here so I don't know anything about that. FWIW, I do carry ID. Well, I carry a donor card with my name on it