[SwellJoe]

To pile onto the anecdote wagon:

The heaviest pot smokers I know (and I know a lot, though I don't generally use, myself), will consume it as much as four or five times a day. As you note, one "usage" looks like a few hits off of a pipe, bong, or vape. It seems to be self-limiting, even in people with a history of addiction.

I'm not gonna suggest pot doesn't have negative consequences; the heaviest users I know also have motivation problems (but so do I, sometimes, and I don't do any drugs) which maybe contributes to them often having shitty jobs and a difficult hand-to-mouth existence. (But, that is correlation and not causation. Maybe the economy is shit, and young folks today have a hard time finding good work. Maybe smoking pot just makes it bearable.)

What's interesting to me is what happens when a pot smoker can't get pot. Among my friends, cigarette smoking goes way up, drinking goes up measurably, and use of other drugs goes up. I'd be willing to believe pot is a good tool for helping people quit more dangerous habits. People who need something help them get through stress/anxiety/pain (emotional or physical) will find something.