I carry whenever I legally can. I'm not clairvoyant. I have no way to know if today is more likely to be my unlucky day than any other day.
As for avoiding risky behaviors, I already do that and continue to do that even when I'm carrying a gun. I might be carrying a gun, but I still don't want to have to use it. As a rule of thumb, if I think I might need a gun, I don't go there or do that.
As I see it, carrying a gun for self defense is for that last small bit of uncertainty that can not be otherwise eliminated.
"It is long been a principle of ours that one is no more armed because he has possession of a firearm than he is a musician because he owns a piano. There is no point in having a gun if you are not capable of using it skillfully." -- Jeff Cooper