In the past, I have smoked quite a bit of marijuana and I can attest to the fact that long term use does impair brain function and just makes you feel terrible in so many ways. Luckily that is all in the past and I feel that my body and brain has recovered from most of the damage that was done.

Interesting find. I know people, successful people, in positions of education, medicine, and other careers making 100K+ annually for many years with no impairment. By no impairment, I mean their memory and decision making skills seem great with almost no fault. Brain damage, that's difficult to measure in these types of people. Perhaps, some are positively affected, while some are not.

Then again, I've known people that used cannabis and had problems in any type of school. The educated cannabis users often know how to control the habit, instead of the habit controlling them.

I don't do it due to lack of benefit.