Researchers say that the sense of smell is the most powerful of the six senses, and the most directly wired to the brain.

That’s why a whiff of something from your past, like your grandmother’s couch, your elementary school cafeteria, your father’s after-shave, or the sunscreen from your first trip to the beach when you were six, hits you so powerfully.  It’s why researchers say women choose their mates, in part, –not because of the expensive colognes (sorry, marketers) because of inborn, natural scent.

I had never thought much about the incredible power the nose has to smell until my third pregnancy.  I suddenly developed (along with unbearable, 24 hour a day nausea) a new and dog-like olfactory superpower.  With my heightened sense of smell came both good and bad things.  I could suddenly smell (and taste) things ten times more powerfully than I usually could.

And most things stunk.

I had to hold my breath while I shampooed my hair.  I had to hold my breath to kiss my husband!  My son’s hair, even freshly cleaned, suddenly smelled atrocious.  I could literally smell people’s breath, if they were conversing in my direction, from across a room.

I could smell the conditioner on my daughter’s hair as she went from the bathroom to her bedroom– across the whole house, a hallway and a living room away.  I could smell mildew in almost all of our bathtowels.  I could not even be close to anybody’s feet.

One night, I asked my husband to close the bedroom window because of the powerful stench of a skunk outside.  He smelled nothing, didn’t believe me, but humored me.  The next morning, as he drove down our street, about a block away, he smelled it.

My heightened sense of smell was one reason that I couldn’t enjoy food; it wasn’t only because of the “morning sickness” (24 hour nausea).  It was because of my new smelling and tasting superpowers.

The bread I usually loved now tasted like preservatives;  I had to start buying fresh-baked, un-preserved loaves.  Canned soup tasted like so many chemicals;  I had to start boiling my own chickens and vegetables.  I developed an aversion to many foods– even chocholate; it tasted and smelled oily, waxy, and off-putting.

When I craved my favorite soda, my husband brought it home for me; but suddenly, it was inedible.  It tasted like chemicals, as if someone had added window cleaner to the mix.  I had to quit putting on makeup, because even the smell of the mascara and the taste of the lipstick turned my stomach.  I know you think I’m exaggerating, but I’m not.

And then, I developed this weird nausea-by-association that went beyond smells to colors and objects. Anything that I had been doing that first week of nausea re-triggered the nausea in overwhelming ways.

I had bought a pea-green sweater the week before the “morning sickness” started;  now that sweater had to hang in the back of the closet, hidden, because just looking at it made me feel sick.  Looking at the covers of the pregnancy books and baby-naming books, that I’d read when I first began my nausea and nasal superpower phase, made me queasier than ever.

Even a plastic box that was the exact same color as the green sweater, that had nothing else to do with pregnancy, made me squeamish.

There must be a reason (science is still working on this one) that pregnant women often have such extreme olfactory awareness, and the associated nausea.   Maybe it protects the unborn baby from unhealthy things by creating a smell-based wall of revulsion between most things and the mother.

But what about the rest of us?  Why do we need to smell?

Maybe the biggest reason is just plain enjoyment.