The Netherlands, anno 2000
I saw a few American tourists having a bad time in Amsterdam, having smoked far too much.
One poor fellow was in Coffeeshop Johnny, immobilized. He was about 20 years old, sitting at the one table with his agonized head in his hands. His friends were trying to get him to stand and go outside for some fresh air, but he wasn't able.
I saw that kind of thing happen elsewhere too. Invariably, it was an American, apparently "living it up" in the fabled libertine atmosphere of The Netherlands. Most tourists, of course, were just having a good time and a quiet buzzI wouldn't want to give the impression that I saw a great number of people getting wrecked out of their heads. But it did happen.
I was sitting at the bar in Coffeeshop The Rookies once when a fellow who'd gotten up to leave was walking behind me and passed out on his feet. He fell underneath the bar counter against the bottom of my stool. I attempted to help him, and to talk with him; staff members laughed. I told them that's not very nice, but they just shrugged. They see it all the time.
Also at The Rookies, a young American fellow fell asleep at a table with a beer and a bong. His poor girlfriend was waiting for him to wake up. Sleeping in a coffeeshop is always against policy, and the staff attempted to wake him, speaking to him loudly from across the counter. He didn't respond. One threw a coaster at him, and he popped awake. He picked up his glass and took a drink of beer. The staff laughed at him. His girlfriend was embarrassed.
There was a young woman at coffeeshop The Noon who had clearly smoked a bit too much, and got frantic. Relative to nothing obvious, she stood quickly. She upset some glasses and cups, made odd noises, and seemed to see things. That was a strange one, and most people in the shop sat in mute discomfort. Marijuana is not hallucinogenic when smoked, and this woman seemed to be having some trip-like experience. Staff encouraged her to drink sugar-water.
I don't know the effectiveness of sugar-water. I've had some dizzy hard times, but have never attempted to take anything for it, aside from deep breaths and an occasional rest (voluntary or otherwise.) Water itself is good, but probably only time will decrease the effect of the drug. However, time always works.
There is the possibility, of course, of organic and/or psychological problems, and marijuana can certainly complicate matters.
In Holland, the potency and availability of smoke is a danger to some people who are normally perfectly sane, and maybe even know how to smoke. The Dutch legal solution of tolerating "soft" drugs is an arrangement that offers freedom. This freedom demands something of the individual. You have to be a cool head.
I lived in Amsterdam from May until December of 2000.