system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we become noseblind?

After long and continuous exposure to one smell, you stop smelling it. A perfect example is house smell. Your own house most likely doesn’t smell like anything to you, but if you enter anyone else’s house, they have distinct smells.

What is the actual mechanism behind this? Why does this mechanism occur? What is its purpose? Is our nose “wearing out”? This doesn’t happen with other senses.
gpt
Do you know how if you're in a noisy environment, but with the same sound (say, jet engines on an airplane droning on, or white noise when in your bedroom), you hear it at first, but after a certain time of exposure, you "tune it out"? Your olfactory (smelling sensation) system does that, when it receives the same stimulus over a protracted amount of time (the same odor molecules being detected by your nerves and tissues, over and over). The nerve cells in your nose simply stop sending/stop sending as much "reporting" of the smell molecules to your brain.

There is a belief that this is an evolutionary advantage (being able to tune out repetitive stimulus) so as to not get distracted and pay attention to other, newer things in your environment (like, noticing *other smells*).