This article was originally published by VICE Netherlands.

Maybe you, like me, decided at some point in your life that you'd had enough of soft drugs for a while. Whether this was the beginning of a smoke-free existence or just a hopeless case of hubris is irrelevant here; the point is that you stopped smoking weed for a bit. When you did, you probably also experienced a plethora of positive effects: You felt more energetic, found it easier to remember things, and stopped spending $20 a day on cheeseburgers and Doritos.

A few days after I quit smoking weed for the first time, I started dreaming again and those dreams seemed more vivid than ever. I realized that as a stoner, I actually hardly ever dreamt at all, and that the few dreams I had weren't half as intense as my dreams these days. What's up with that?

I decided to call Dr. Hans Hamburger, neurologist, somnologist (sleep expert), and head of Holland Sleep Research—a specialist research center for sleep disorders in the Netherlands.

According to Hamburger, this resurgence of dreams is common among former smokers; weed suppresses your REM sleep. When you put your rolling papers, pipe, or vaporizers away for a while, your REM sleep suddenly gets the free rein it had before you became a superficially sleeping stoner

Because I'm not a somnologist myself, I asked what REM sleep exactly is. "Every night, you go through about four or five sleep cycles," Hamburger replied. "Each cycle takes about ninety minutes, during which you go through different phases. There's superficial sleep, deep sleep, and finally REM sleep. During that REM period, you have most of your dreams. You don't usually remember your dreams if you continue sleeping. The last REM period just before you wake up takes the longest—and you'll only remember the dreams you had in that time if you wake up during it. If you don't wake up during the REM period, you won't remember a thing."

Does this mean you can't remember anything at all when you're sleeping? The answer seems to be no. "You only remember the things that happen while you're awake," said Hamburger. "We don't remember the things that happen while we are sleeping, because we're in a lowered state of consciousness. That has something to do with the fact that when you're asleep, you're processing the memories of things that happened during the day and essentially filing them away in your brain."

Dreams help you sort through the thousands of impressions and images you encounter every day. When you smoke weed regularly, that function is also suppressed. Dr. Hamburger confirms this: "By smoking weed, you suppress the REM sleep, and with that you also suppress a lot of important functions of that REM sleep. One of those functions is reliving the things you have experienced and coming to terms with them, as it were. Processing all kinds of psychological influences is something you do in REM sleep. You also anticipate the things that will happen the next day or the days after that. While you're sleeping, you already consider those and make decisions in advance."

The less you give your brain the change to sort this shit out during REM sleep, the more dazed and confused you are during the day. This may explain why the seasoned stoner will often put off tasks and decisions until the very last minute: You failed to anticipate these issues properly, which is why you're late filing your taxes again, or can't remember where you left your house keys.

Alcohol, surprisingly, has the opposite effect: If you go to bed shitfaced, the phases of REM sleep last longer. That is not to say that drinking two bottles of vodka before going to bed will help you get a good night's sleep. "Too much alcohol suppresses the deep sleep and gives you more REM sleep, but it makes you more restless and wake up more often. If you drink way too much, you'll be twisting and turning all night and keep waking up," said Hamburger.

Anyway, back to smoking weed. The effect pot has on your night's rest is clear. But why are your dreams so hyper-realistic and feverish after you stop smoking?

"If you've been taking a drug that suppresses a certain phenomenon for a while, then that phenomenon will come back stronger when you stop using that drug," explained Hamburger. "That's what we call 'the rebound effect'—which is also noticeable in people who take a lot of sleeping pills. If they stop taking those, they often get very strange and intense dreams. That is also often the reason why people keep taking those sleeping pills—they become dependent on them, which is to say, addicted."