I know tons of potheads. All of them barely finished high school or didn't at all. They have mental issues period. I know someone who was very intelligent then smoked weed everyday. Now he hates the world turned his back on Jesus, would rather smoke weed to feel good than go get a job to support himself. He got into Ohio State and got onto the golf team. Skipped practices to smoke pot. Couldn't do the schoolwork high so why do it at all. I had three roommates in college who started to smoke weed. Two of them dropped out and one almost failed out. He quit pot and ended up barely graduating. He is doing alright now but almost lost his future because of it. The fact you watch a youtube video and believe everything it says is funny in itself. The thing is our body is our temple. And putting anything harmful in your temple wrong. So from a Biblical standpoint it is wrong. I can almost predict your argument against it.
I have to say your experience is not mine at all.
I know a lot of people who use drugs of various types. Some of them are "potheads" I would agree, but far from all of them. I'd say at least half of the people I know who ever smoke pot do so occasionally, and it does not mess up their life. They have good jobs, earn more than enough money to support their families and then some, they do not shirk on their responsibilities.
I have never met anyone who was "fine" before they started using marijuana, and then started using it and went downhill. I know a lot of people who had problems before using the pot, and some of them tried to use pot as "self-medication," and it either didn't help or made it worse. But all of the people I know who use pot and are like the "losers" you describe were that way before they started using.
I'm not saying pot is good. I'm just saying your experience, that 100% of the people who ever used drugs ended up ruining their lives. ... that just doesn't mesh with my experience or with national statistics. Even the most conservative polls I've seen the TOP % of drug users who end up lost like you describe, maybe 75% -- which is still too high, but not nearly the 100% you're reporting.
And most polls show more around 50%, some more, some less. Of course, I would tell my son is it worth a coin flip to throw away your life?