I just know that a lot of the readers of this blog will appreciate today's XKCD, even if they don't already follow it.
Description: A person saying "The sleep deprivation madness worsens. Things seem unreal. Am I even awake? Maybe I'm dreaming."
The person approaches a tree with a squirrel climbing on it. The person says "I'm pretty sure I'm hallucinating this tree. But what if I'm hallucinating that I'm hallucinating and I'm actually totally sane?"
The squirrel replies "Listen. I wouldn't worry about that."
XKCD usually adds an extra comment or punchline as alt-text. Today's is "I'm not listening to you. I mean, what does a SQUIRREL know about mental health?"
I loved this strip on so many levels. It's a perfect depiction of the kind of existential worry that you only encounter when you're sleep-deprived and/or drugged up to the eyeballs, when your grip on reality is slightly fuzzed and you start to ponder the nature of reality... after all, if I am hallucinating, I will be the last person to know that my hallucinations aren't real because they'll originate from my own brain! Maybe I'm hallucinating Steve, or hallucinating the internet...
(That's what usually settles it for me. I could not possibly hallucinate even half the stuff I see online.)
(edit for picture width, although I'm still not sure I've done it right.)