People often ask this question. I guess because it happens to us all at some point or another. You buy a new perfume because you love the smell. But after wearing it for a while – maybe a few weeks, maybe a month – you can’t smell it anymore. But other people can.
Or you idly wonder why people with body odour don’t notice it, but that you never stop smelling rotten food. Or burnt toast or hair.
This is called Olfactory Adaptation or Habituation. It is part of our survival instinct. All animals use scent as a way of detecting danger. All new smells are potentially dangerous so you can smell them. Once your body figures out a smell is not a threat, you cease to smell it anymore, in order to allow your nose to sniff out any other potential dangers lurking around.
Rotten food (eg eggs, fish, chicken) remains a danger so those smells tend to linger in your nose for longer.
Smell is one of the senses that we tend to take for granted and not think of very often. But smells can be so evocative and take us back to happy or unhappy times. I have never forgotten the smell of my mother’s White Shoulders perfume, or my dad’s Old Spice. Or my first perfume, Goya’s Aqua Manda. Or the relationship where I exclusively wore Calvin Klein’s Escape because my boyfriend loved it. Or the smell of Body Shop Dewberry that my students used to wear when I briefly taught in a high school. But at the time I did not even smell any of them after a while.