+1 to this. As a long time cannabis user who is quite skeptical of many of the purported health benefits, this is one I’m not at all skeptical about. It’s actually just the other side of the coin of the degraded short/mid term memory that is a well known downside of habitual cannabis use. But as someone with frequent, vivid nightmares when I’m sober, I can attest that cannabis effectively blocks my ability to remember most dreams - which again is a mixed bag, as I enjoy recalling happy or neutral dream, but when I’m stressed being able to basically opt out of vivid nightmares is a huge boon.