It isn't about being afraid, irrationally or otherwise, it's about recognizing the possibilities and being prepared. I've never HAD to get a fire going to save my life, but I still carry matches in my pocket. Just because I've never been hypothermic doesn't mean I won't ever be.
I haven't been afraid of bears since I was 12, but I'm not in denial about the potential dangers.
You still don't understand the difference between REAL and POTENTIAL. The potential danger of the sun exploding is kind of huge. The real danger is not worth worrying about.
REAL is the word I keep using. The fact that something has a large potential danger does NOT make being constantly prepared for it rational. Only preparations for REAL dangers is rational. Recognizing the difference between real and potential risk is not denial of the potential; it is just being rational. If you look into the Survival and Disaster Prep forum you will see all sorts of examples of preparation for potential disasters that just aren't realistically likely.