Here’s what science has to say: Sorry you’re (allegedly) stinky. You might not realize it, but there are probably lots of smells you’re used to — including the smells of your own body and its byproducts. That’s why the bathroom always seems way smellier after your roommate uses the toilet. Trust us, they feel the same way. There are two big components to this phenomenon, and one happens very quickly: We experience smell when molecules bombard receptors in our noses, and if they’re overrun with the same smell for a few moments they’ll tire out. It’s like a refractory period for your nose. That’s why you might think that your roommate’s garlicky meal smells super pungent when you first walk in the front door, but stop noticing it a few minutes later.