The craziest part of all is that you likely will have no idea that you reek of cannabis.

Similar to smoking cigarettes, it’s near impossible to detect the smell of weed on oneself after getting high or being around those who have done so.

It’s why parents can tell when kids are stoned even if they’re acting “normal,” and it’s a common excuse used by cops to search cars even if the driver claims they haven’t been smoking.

Research into this phenomenon is still relatively sparse and incomplete. For instance, we don’t know how long it takes for one to become immune to the smell of weed or how long that stench lingers in the fabric of our clothes.

Pamela Dalton, a faculty member at Monell Chemical Senses Center in Philadelphia, said the dearth of this kind of research is largely because marijuana, though legal in some states, is still considered a controlled substance on the federal level.

Getting approval, not to mention funding, to study the recreational use of cannabis can be “incredibly difficult,” she said.

But for someone who has been investigating environmental odors and chemical sensitivities since the ‘90s, Dalton is not totally mystified as to why we can’t smell ourselves when we reek of weed. She’s pretty sure the reason has to do with olfactory adaptation.

Basically, the molecules released from burning cannabis bind to the smell receptors in our noses, essentially preventing us from being able to detect that specific odor.