Let’s talk about THC. Anyone celebrating 4/20 will be riding high on the compound’s mind-altering effects, delivered by way of that sticky icky-icky. But contrary to what rapper Mick Jenkins will tell you, THC doesn’t stand for “The Healing Component,” although its obvious why he’d think it: Tetrahydrocannabinol mimics a compound called anandamide, a naturally occurring brain chemical also known as “the bliss molecule.”

Occurring naturally in the resin of both Cannabis sativa and Cannabis indica, THC is thought to be their natural defense mechanism against plant-fiending predators. Clearly, nature didn’t plan for human herbivores — or maybe we were already too stoned to recognize poison when we first saw it — who have been smoking and eating the plant to reap THC’s effects for over three millennia.

Over the years, we’ve gotten more creative with THC extraction, adding vaping and skin absorption to the ways we get high, but whether you’re scarfing brownies, hitting a grav’ bong, or dabbing shatter, ultimately it makes no difference in the way you get stoned: They’re all just highways for THC to roll up into your bloodstream and park in your brain.

Once it’s in your system, THC makes its way to the brain’s cannabinoid receptors, which are found scattered among areas of the brain that process thoughts, memories, and pleasure, together with coordination and the perception of time. Grabbing hold of THC molecules, these receptors go into overdrive — after all, THC is not what they evolved to bind — disrupting the normal mental and physical functions usually controlled by those parts of the brain. We all get a little dumb after THC binds in the brain’s cerebellum and basal ganglia, which control our reaction time and motor skills. Likewise, memory formation gets hazy when the molecule binds receptors in the thought-processing hippocampus. These lapses are a small price to pay for the THC-triggered upside.

Ultimately, the THC signaling cascade also triggers the release of larger-than-normal amounts of euphoria-triggering dopamine, the chemical at the heart of the brain’s reward and pleasure system, which also governs our love of food, sex, and chocolate. Throwing this system off-kilter means we get more reward for none of the effort, ultimately, as cannabis crooner Rick James put it, taking us to paradise.

When you’re not stoned, the brain’s cannabinoid receptors are usually busy binding anandamide, the brain’s natural cannabinoid. Its name, inspired by the Sanskrit word for “bliss” or “extreme delight,” is largely aspirational: Its effects on pleasure and motivation, though similar to those of its marijuana-bound counterpart, aren’t nearly as potent, as far as scientists can tell.

Depending on how dank a strain you’re smoking, bud can contain anywhere from a soft 0.3 percent THC by weight to a massive 15 percent. If you deal with dabs like shatter, waxes, or resins, which concentrate THC and related cannabinoids like CBD, the THC level could reach up to 80 percent.

So far, nobody’s ever died from a weed overdose, but getting too high — especially off edibles, which have highly variable THC levels — can land you in the emergency room with anxiety, hallucinations, palpitations, and vomiting, as inexperienced weed tourists in Colorado have unfortunately discovered. You can smoke weed every day. Just don’t overdo it.

Photos via Wikipedia