Is it normal to not be turned on by the human body?

How normal is it to not be turned on by the human body UNLESS it's in a sexual act? I've seen so many people that just see a pair of tits, ass, dick etc. and are completely turned on! I can look at a naked man or women and not be turned on at all. In fact I look at nude art and pin ups because I think there fun and quirky but even if there in a very sexual position, i'm not aroused. I find the human body sometimes beautiful but most of the time nudity doesn't bother me or turn me on at all. Now, if I see porn then of course I'm going to be slightly turned on but then again it has to be the right type of pornography aka something that's obviously depicting sex an is hardcore etc. IDk, it just puzzles and annoys me how some people can't even look at the naked human body in an anatomy book or in art with out it being sexually arousing to them. Maybe, I just have a more mature way of looking at sex. *shrugs*.
i mean considering there's nudist colonies and they aren't turned on by seeing there neighbors naked i guess its kinda normal, but still i just want to hear other opinions.