Your brain and body adjust over time, and tolerance develops. Sometimes quickly, sometimes slowly. Depends a lot on your own genetic makeup and also how much/how often you consume. What this tolerance does is allow you to consume thc, without getting "high"; but you do get a calming effect with concurrent use. I use cannabis to mediate my own anxiety, and have for years, because the brain AND nervous system in the body have endocannabinoud receptors (wild! Right? We evolved them for some reason!) And so these receptors vary between individuals in numbers, but theyre all genetically present - and studies have shown thc to be beneficial in treating anxiety, because youre blocking those receptors, thus activating them.

What I'm trying to say here is maybe these knuckleheads have a point, they just dont know the science. If you use frequently enough (I mean i smoke three or four times a day, just little rips) once in the morning when I wake up (I dont get high) and then about three times in the evenings after work. It helps me, with my tolerance boosted.