The thing in question: becoming a complete idiot during periods of physical exertion.
Backstory! Today I was helping a friend move down in Madison. She's kind of a hoarder, and so there was a lot of stuff, and it was a hot and humid day. Also relevant to this story: I am an Eagle scout, and therefore have had to demonstrate my knowledge of common ailments that can suddenly come on while out in the boonies. Like heat stroke and dehydration. Also, not even two weeks ago when I was in the hospital getting diagnosed with pneumonia, I was so low on fluids that they were about 50/50 on using an IV to get me back up to par. If you think this foreshadowing is about as subtle as a Pangalactic Gargle Blaster, you're absolutely right. So yeah. Didn't drink nearly enough fluids, did heavy lifting with my fractured elbow that I was under no circumstances supposed to do heavy lifting with, didn't stay out of the sun nearly enough. And also failed to consider the effects of heavy physical labor in the hot sun, i.e. tiredness, especially in juxtaposition with a 2 hour drive home. I was not a safe driver on this occasion, especially not in a piece of shit car that pulls to the right. At least I realized it in time to pop a couple caffeine pills from the glove compartment before I ran off the road or something.
So, today I was a complete idiot. My hypothesis is that it was related to physical exertion. Provide supporting/dissenting anecdotes in comments, as well as whatever else you feel like responding to from this post.