I’ve known people who smoked regularly in college, the lack of motivation is well known. Obviously not everybody is going to be affected in the same way, by anything.
I thought this was settled science years ago (where particular parts of the brain were effected by marijuana). I thought that was the driving force behind those old commercials where the non-working white adult was living at home like a teenager; I believe they ended with, “With pot, nothing happens...”. It was a play on the character insisting it had no ill effects, but also the fact that they hadn’t looked for a job or done anything else.