Some of my best friends in college were pre-med students.
A group of them has an apartment off campus which was a hangout for many of the other “cool” pre-med students.
Frequently when you entered their apartment the marijuana smoke was so thick you could literally- and I swear I am not exaggerating- get high just taking a step in.
You will find these guys today in the listings of “Best Doctors” in the some major cities.
The dorms I lived in during college, you could smell pot smoke 24/7. I've been torn over this issue for years: pot, booze, etc. should be strictly verboten for kids. For adults, in the privacy of their own homes? That's a different matter.
Haven't been near the stuff in decades. My employer tests new employees as a condition of employment, no skin off my back.