Forget the scent.
I have great use for all my senses. But, if I had no choice but to give up one, I'd hesitantly part with the sense of smell.
My life mainly functions on sight. I need it to drive, to work, to cook. I need it to spend time with my family and friends. There's a reason people say, "it was good to see you." Life can be extremely beautiful and I want to witness and capture the moments of its beauty.
Hearing is also crucial. Words have power and can affect a person on many emotional levels. Just one word from the right person can send someone in ecstasy. Some music can do that as well, and it'd be a shame not to be able to hear it. Plus, thinking about it, if I ever have children, being able to hear would be necessary. If I am doing something about the house, one of the few ways to know that my child needs something would be through their cries. I would also want to communicate with the child, and wouldn't want to miss out on hearing the precious babbles and first words.
Touch matters. If someone is having a tough time, sometimes, all that is needed is a hug. Or even a pat on the shoulder. Maybe all that person needs is someone who'll sit beside them. Simply the slight exchange of nearby body heat can assure a person that someone is there. That they are not alone. As someone who expresses their affection through giant hugs, I doubt I can let that sense go. The world also has too many interesting textures to give up. The smoothness of silk against the body, the roughness of sandpaper. Even the disgusting feeling of something slimy.
As for taste, well, I live on taste. Gluttony is one of the vices I often embrace. Whenever I cook for others, it's important that the food tastes right and I don't give them food poisoning. Also, during social gatherings, enjoying the company and the food is important.
Smell. I'll miss the sense of smell. I'll miss smelling the sweetness of flowers, the freshness right after the rain, the smell of a loved one's cologne, the scent of something freshly baked. But, it's still be the sense I'll give up.
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If I made a test for which sense to give up, despite being a glutton, I would've failed because I would've had to give up taste. But, being the way that I am, this option is impossible.
Imagine a puppy. What do you do?
-You see the puppy.
-You hear the puppy.
-You touch the puppy.
-You smell the puppy.
:: You DO NOT eat the puppy::