Have you tried turning the general statement around to a negative statement? That way it becomes a search for counterexamples. Of course, if this fails it could just be because you're forgetting, but it seems to me that attempting to construct a counterexample would help jog the memory.
This is the public group instrumental rationality diary for November 16-30 (that I've now fished out of my drafts folder, *cough*.)
The poll earlier this month seems to be sufficiently in favor of maintaining the current schedule that extra votes are unlikely to change things much, but if you'd really like to register your opinion, you are welcome to do so here.
Thanks to cata for starting the Group Rationality Diary posts, and to commenters for participating.
Immediate past diary: November 1-15
Rationality diaries archive