Any stupid viruses?

Factual Questions
1

Lots of viruses that cause the familiar cold symptoms. Some are better at it than others, and some viruses, I’m sure, don’t cause any noteworthy disruption at all. Odd though. I’ve never heard of a virus that, rather than giving you a runny nose or a lungful of butter, makes you stupid. Or is there one? I would think it might go unnoticed because nobody can really call in “stupid” so we all have to go to work anyway, debilitatingly incoherent and clumsy as we are. As such, nobody ever thinks to look for a stupid virus. Have they? Maybe one that hijacks the central nervous system or something?

Because I’ve certainly got it bad today.

2

I think the end stage of rabies is dementia-like symptoms speckled with hallucinations. I believe rabies also makes men hypersexual too. I haven’t had virology in ages.

3

Well, a friend of mine had ‘flu’ and the virus travelled to her brain and almost killed her. Her short-term memory is shot now. Does that count?

Viruses will make you tired. When you’re tired, you aren’t your brightest.

4

Well, the symptoms sound right…