"Different palates perceive spicy "heat" at different levels"
Oh for sure. And different "hot" ingredients are perceived differently by different folk too.
My woman and I go out to an Indian restaurant on occasion and if, as we often do, we share a main course as well as the side dishes, we can't go "too hot" as she isn't keen. She doesn't like it "too hot". But, on a number of occasions, she has cooked a dish and apologised in advance for it being so bland, despite her trying and adding loads of stuff to give it flavour; whereas not only do I find it tasty, my eyes are starting to stream due to the large amount of pepper in it that she seems unable to detect.