Interesting people may just be...interesting and unique as themselves, it may or may not be their belief or religion. Some behavior may be like you say, their personal discipline.
I am fascinated with a particular person and I am always wondering what makes him "tick." I can usually ask, but I didn't want to sound like I wanted a gift---mentioning birthdays and such. :) I actually enjoy giving on those days but have had to realize this particular person does not celebrate or indulge in the usual way.
I favorited your post and I will read it several times. It is poetic and meaningful, I appreciate your insight.