The previous comment is still correct: even without weed we dream a lot and don’t record most of it.

Alcohol in our system at bed time impacts sleep as well. We’re consciously at rest (or blacked out from over consumption if that is ones thing) but our body is busy metabolizing.

Poor signal, YouTube isn’t loading. Not sure if the clip is similar, but as I understand it recording a dream and restless sleep from metabolizing substances are separate processes.