Jean Baudrillard and Vilém Flusser walk into a bar.

Flusser starts: 
“Human beings forget that it was they who produced the images. Imagination has turned into hallucination.”

Baudrillard mumbles:
“Y’know, for me, the world is — an illusion; it is not reality.”

Both nod in sinister agreement and empty their glasses in one gulp.

After a while, Douglas Adams the bartender appears, pours them another drink and says:
“Cheer up, lads! Reality is what refuses to disappear, even if you stop believing in it.”