When you are in the realm of classical physics (imprecisely called "reality," because the other two kinds of physics are no less real, only far from our everyday experience), it's only normal that you are a rationalist. The alternative is to be irrational which is only an euphemism for being more or less insane. But I joyfully accept becoming irrational as soon as I step into what's the literary equivalent of relativistic and quantum physics. It is not only normal behavior there, but very desirable too. Without being irrational you would never achieve anything in the art of the fantastic. As a matter of fact, the more "insane" you are in that other realm, the better. That "insanity," however, should be as controlled and coherent as possible in order to provide the best narrative results. And that is where the rational part of the mind helps enormously. So, it is only on an intensive cooperation of the two opposite poles, the rational and irrational, that the process of fantastical literary creativity is properly based.