Anatomical anomaly

So here's something that I've been wondering about...
the human body is symmetrical along the median plane (for the most part) and there are many parts that there are two of, one on each half of the body. Many of them make sense:

ears- so you can hear on either side of you, and you can easily turn your head to position yourself to tell where a specific sound is coming from, without even thinking about it.

eyes- near the front of the head, just enough to the side to have a wide range of vision to the sides of your head, but facing the same direction enough to have an overlap to get good depth perception.

hands/feet, fingers/toes, etc- two hands help you grasp things on either side of your body, two feet to help you balance.

all this is basic anatomy, and not just with humans, but most animals. you can split an animal straight down the middle and take a look at the basic structure of the two halves and they are equal. I'm not talking internal organs here, though some of those are mirrored too (lungs, ovaries/testicles, kidneys). nobody disputes or questions any of this.

my problem is......nostrils!

why do we have two nostrils? I can understand eyes, ears, etc because there are practical purposes as noted above. but two nostrils? I don't see the evolutionary benefit of having two smaller nose holes instead of one bigger one:

-wouldn't air flow to an animal's lungs be more efficient with one giant nostril than two smaller ones?
-I would think it would be more difficult to clog one giant nostril than two smaller ones (how many times have you blown your nose in the last week?)
-there's more skin/surface area with two smaller nostrils, isn't it bad enough that we lose a good portion of body heat through our head, we have to have more surface area to do so?

I think we should be a race of nasa-clopses with one giant nostril who could breathe faster and not have to spend as much on kleenex. AAAAAACHOOOOOO!


edit: hahaha now all the random ads are about medical books and anatomy :)