Actually, on further consideration, I'd be inclined to leave it in, with a note to the effect that stupidity with biological causes is often curable. I don't know what fraction of stupidity is caused by health problems, but it definitely doesn't take anything nearly so dramatic as a stroke to cause mind fog, and I suspect it would rank highly on any cause-of-stupidity diagnostic checklist. In particular, subtle dietary deficiencies do it too.
Done. I note that I just reversed a decision twice, and might have made the correct decision quicker had I tried harder for goal-related insight before replying.
Adding "feeling like you're blind and must be led around by more observant people"
In Anna’s recent post, she talked about training your mind to notice when it wasn’t curious about something and scream “Error! Look for a different way to do this” in such cases. Johnicholas and TheOtherDave's list of what stupidity feels like also looks useful for this purpose. I'm creating this post to make a more comprehensive list of feelings which indicate that people should reanalyze different possible paths to make sure that the one which they're taking is the most effective one to their objective.
Please suggest additions to the list in your comments -- I'll move them up here (along with links to further explanation, if given.) Keep in mind that your description of the feeling should be as illustrative as possible. For example, "feeling stupid" is unhelpful, while "you feel like you've taken a wrong turn into a never-ending tunnel" is better. Of course, metaphors which are immediately understood by some people may not be so easily understood by others, so try to give a more detailed description of the feeling if other people express that you're probably saying more than they're hearing.
List: "Error! Look for a different way to do this" if you feel like: