I've found that I can have a lot of patience and interest in mental work while stoned, but I forget a lot of it after it's done. Weed is a mild amnesiac, and for someone with otherwise very good memory, this is noticeable. This may be great if you're doing something soul-crushingly boring, but a better strategy is to avoid that sort of work to begin with.

IANAN, but I suspect that in your case, weed is helping because of its indirect action on the opioid system, and despite, rather than because of, the characteristically "weedy" effects. Have you self-medicated with any other euphoriants?