Every time someone says "just relax," I think about how relaxing is both a state of being and a verb in motion, which makes it paradoxically stressful.

"Just a heads up: that coffee we gave you earlier had fluorescent calcium in it so we can track the neuronic activity in your brain. There's a slight chance the calcium could harden and vitrify your frontal lobe. Anyway, don't stress yourself thinking about it. I'm serious; visualizing the scenario while under stress actually triggers the reaction."